Aberystwyth to the Wirral Coast

We're 1,200 miles into our epic journey around the entire coast of the UK.

And as I get into my stride, step by step, mile by mile,

I'm getting a real sense of the constantly changing rhythms in the monumental geometry of our coast.

It's like walking through a vast gallery of natural sculpture.

This is the sort of thing I'm talking about...

the almost perfect arc,

40 miles across, of Cardigan Bay in West Wales.

It might look serene and unchanging today, but down the centuries

this coast has seen more than its fair share of travellers.

And of enterprising architects and engineers, hell-bent on manipulating it to their own ends.

We've got some fascinating stories to tell.

Helping me to tell them is a small but dedicated team of experts.

Writer and Historian Neil Oliver will be examining the ancient legend of a Welsh Atlantis.

Zoologist Miranda Krestovnikoff is on the lookout for a rare traveller to our coast...a six-foot reptile.

While anthropologist Alice Roberts is on the trail of the elusive miners

who worked the biggest prehistoric copper mines in the world.

It's not quite right.

And I'm even going to have a bash at a bit of Welsh.

This is the story of Coast.

I fyny fo'r nod!

Onwards and upwards!

On this fourth leg of the journey,

we'll be travelling the 540 miles

from Cardigan Bay up to Anglesey,

and along the north coast of Wales to the Wirral.

But our starting point is here in Cardiganshire,

where village after village clings to the coast like limpets.

Inland lies harsh, unforgiving territory.

And until very recently, these people depended for their livelihood, their future...

on seas beyond the furthest horizons.

The village of Llansantffraed is typical.

For a small village in Wales, this place has a remarkably outward looking past.

It almost defies belief that dozens of young lads from this village

would have been more familiar with Cape Town and Melbourne than London or Cardiff.

These people were real travellers.

A lot of those travellers never made it home.

Some of these graves are empty,

but memorials in the little churchyard here of St Bridget's

a reminder, a little glimpse, of their adventurous spirit.

Look at this.

"In loving memory of Evan Jones."

He was a master mariner, Llong Lywydd, and he died in Buenos Aires, and was only 39.

Captain David Morgan, died in the winter of 1874, aged 43

at Jamaica. From Cardigan Bay to the Caribbean Sea.

Over here, two generations of the same family seem to have died beyond distant seas.

We've got Evan Rees, who died at Ballarat in Australia in 1865,

and then his grandson also named Evan Rees

drowned on a voyage between Philadelphia and Havana in 1899.

He was only 28 years old.

Ships were tattooed onto the DNA of these people.

Even their graffiti was nautical.

All over the world, the respect seafaring people have for the sea

is often expressed in superstition and legend.

Noah's flood, Lyonesse, Atlantis.

Our historian, Neil, is on the track of a Welsh version of the story of a kingdom lost to the sea -

the legend of Cantre'r Gwaelod.

For centuries, a story's been told that that entire bay down there below me

was once fertile land, now lost to the sea.

Now, it's easy to dismiss a legend like that as a simple story for simple folk.

But now, academics, archaeologists, scientists

are starting to think the unthinkable.

Is it possible that behind the story, and many others like it

from around the coast of the UK, is a nugget of truth?

Cardigan Bay certainly has a number of physical features

that seem to testify to the truth of the legend of a Welsh Atlantis.

And who better to show me round them than folklore expert Twm Elias.

This thing is unbelievable, it looks for all the world

like somebody's downed tools half way through making a three lane motorway out into the sea!

What is it?

Well, this is Sarn Cynfelyn, and it's a great undersea ridge

which goes out about eight miles in that direction.

But what it is, is the surface part of a great undersea dyke,

which is to enclose a fabled land called Cantre'r Gwaelod,

of legend, of course, you know?

And that land used to stretch right from the tip of the Lleyn Peninsula, Bardsey Island up there,

right down the length of the bay to north Pembrokeshire

out in that direction.

It was a fabulous, very rich land,

with 16 lovely townships and so on in it.

And where is it now? I see only sea.

Well, yes, it was inundated. This is the point, you see?

And as with similar legends from the Celtic Seaboard, on a clear night, you're supposed to be able to hear

the bells of Cantre'r Gwaelod tolling in the watery deep.

Oh, yeah?!

But Twm promises me there are other silent witnesses

to the possible truth of the legend of a kingdom lost under the waves.

So why have we come to Borth Beach, Twm?

Even though we're only a couple of miles away from where we were at Sarn Cynfelyn before,

this place has got its own secret, and before long, the time and tide will reveal that for us.

I have never seen anything like that in my life.

Truly amazing, man, isn't it?

At first sight it looks like some sort of washed-up sea creature,

it's only up close that you realise what you're looking at.

It's actually the roots and base of a massive tree.

I'm not talking about a sapling.

It would've been hundreds of feet high.

It's like the world's gone mad.

It's like the sea's here and the land's up there, so what are the trees doing out here in the sea?

Twm, how can this be?

It's absolutely amazing, isn't it?

Huge tree trunk like this but that's not all of it,

because there's a large area of it going right out to sea in that direction.

And if you want proof that Cantre'r Gwaelod did exist, here it is, in fact.

And no wonder people are coming up with stories.

If your beach is littered with trees that are swallowed up at high tide,

and if your neighbours have got beaches, there's going to be some sort of explanation, isn't there?

Well, there has to be. The legend does explain it.

So is this folk story of a Welsh Atlantis

a pretty tale to entertain the villagers, and perhaps explain natural phenomena?

Or is it something else?

Something much more powerful?

Could it be that what the story represents is deep history,

a folk memory of a real event that didn't just overwhelm Cantre'r Gwaelod,

but that laid waste to vast swathes of the coastline?

Let's put the legend to the test.

This is the Dyfi Estuary that spills its beauty out into the sea between Borth and Aberdovey.

And it's here that expert on ancient trees,

dendrochronologist Nigel Nayling, together with some of his students

from Lampeter University, have been doing work on yet more trees that have only recently been exposed.

What a place you've found, Nigel.

A bit muddy, but it could be worse.

Yeah. How long has this place been known about?

Only a couple of decades.

We're looking at a place where a meandering river

has dug down into ancient levels

and it's exposed something we call, generically, "submerged forests".

-Right.

-And it's a pretty ancient one.

This tree must have been here 5,000, maybe even 6,000 years ago.

Trees flourished in this area before rising sea levels

made it impossible for the trees to thrive and grow.

If we'd been here when this tree was in its prime, what would this coastline have looked like?

It would've been radically different.

In terms of position, it would've been a long, long way away.

It may well have been over a kilometre, five kilometres even,

further out into what we now call Cardigan Bay.

Because I imagine a change like that being something that happens over...

millions of years, a coastline changing its shape. But not here?

At certain periods, I think the change could have been quite dramatic.

Dramatic so that it was changing the lives of people living here.

They're in a world where they're threatened.

If coastal environments,

like grazing environments for their livestock became inundated,

that would result in an impact on the human population here, in a generation.

It's the sort of thing embedded in prehistoric communities.

The sort of myths and tales that we find today

may have their roots not only in medieval documents,

but even far further in the past when this rapid coastal change was occurring.

We're in a particularly good example of a submerged forest,

but these do exist around many parts of our coast.

Further north in Scotland we see less relative sea level rise because that part of the land

is coming up in response to a release from the weight of ice after the last Ice Age and is still doing so today.

Whereas in the south, generally, we're sinking compared with the sea.

We still are today, and we have been for the last 10,000 years.

-Scotland's rising again!

-Scotland is doing very well.

It has raised beaches.

South England and even up here into mid Wales, we're seeing areas that are submerged.

This tree is a glimpse thousands of years back into the past,

to a time when the world here changed so quickly

that trees like this were caught like bugs in amber.

I suppose this is a story about resilience -

the resilience of these trees and of the myths and legends they helped inspire.

Leaving the dolphins of Cardigan Bay

to play in the ancient forest,

I'm now heading north past Aberdyfi and Tywyn

until I get at last to the picturesque splendour of the Mawddach estuary.

Although the peak of Snowdon itself is 20 miles in that direction,

we're already in the Snowdonia National Park.

And this is one of the best coastal views in Wales.

Behind this watery foreground of the Mawddach estuary

rises one of my favourite mountains in the United Kingdom, Cadair Idris.

The chair of Idris.

Snowdonia has been a national park since 1951,

and although it's usually thought of as a mountainous landscape,

it actually includes 23 miles of stunning coastline.

Take the train across the estuary, and you'll be in Pwllheli in a jiffy.

But this is one journey I want to last.

This bridge was built in 1867 to carry the railway line across the estuary.

But walkers are allowed to cross it too, for a price.

Hello, there.

-Hello, how are you today?

-I'm good, thank you.

-Good.

-How much, please, for one pedestrian with a lightly loaded rucksack and an umbrella?

-60 pence, sir.

-Thank you.

-Thank you very much.

Do you ever get toll-dodgers? People who walk up and accelerate before paying?

Oh, well, yes, there is a few that do that, but not many.

-Fair play, most people will pay.

-What do you do about them, chase them?

Yes, as you can see, I'm built for speed so I catch them by the end of the metal section.

-And they don't do it twice?

-No, no, not with me being here, no.

60, 80, £1, and another one makes two, and there's your ticket.

Keep that if you're walking back, it will act as a return.

-I'm on a one-way journey.

-Oh, a one-way journey.

Oh, never mind.

-Keep it as a souvenir.

-Bye.

-Bye-bye.

It's only when you get across the bridge to Barmouth

and follow the coast to Harlech that you begin to realise

your 60p toll was the bargain of a lifetime.

Here there's room to relax,

room to breathe...

and rooms for all.

Harlech itself, like so many towns I want to visit in North Wales, is dominated by its castle.

Begun in 1283, it was Edward I's little way of saying "thank you"

to the Welsh for revolting.

And it was one of 12 of his castles in Wales to be designed or fortified

by his French master mason, Master James of St George.

Just over the river is another extraordinary example

of essentially foreign architecture that's taken to these hills - an entire Italianate village.

The whole village of Portmeirion was the vision of one slightly eccentric architect,

Sir Clough Williams-Ellis, and it occupied him for most of his life.

He started building in 1925 and it still wasn't finished when he died in 1978.

He wanted to prove that, as he put it,

"the development of a naturally beautiful site need not lead to its defilement".

Was he right?

Well, the purist in me is absolutely outraged by the arrogance of a man

who thought that his own imagination could enhance such a beautiful place,

but the escapist in me is irresistibly enchanted.

But a large number of the 240,000 or so visitors

who come to Portmeirion every year

aren't coming solely in search of beauty.

"I am not a number, I'm a free man."

I suspect I'm not the first person who stood right here and said that.

'I am not a number, I am a free man.'

Patrick McGoohan's protestations that he was a free man, and his unaccountable terror

of a giant white bouncy ball, were central to the '60s cult television series,

The Prisoner, which was filmed here at Portmeirion.

As Number Six, McGoohan's constant persecution by Number Two,

his efforts to discover the true identity of Number One,

and his weekly attempts to escape the village,

kept viewers on the edge on their seats.

Personally, I can't imagine why on earth anyone would want to escape from this little paradise.

Could it be true to say for once that the set upstages the drama?

Clough Williams-Ellis, creator of Portmeirion, called it "a home for fallen buildings"

because so much is constructed from bits salvaged from stately homes.

This, for instance, is the Gothic Pavilion, cannibalised from a Welsh mansion.

The Pavilion is dedicated to a less well-known visionary from a 100 years earlier

who also had a dramatic effect on this part of the coast...

William Alexander Maddocks.

Barely a mile away, as the seagull flies,

you step into an entire landscape forged by the imagination of William Maddocks.

And he had a number of things in common with his neighbour.

Neither Clough Williams-Ellis nor William Maddocks had any real formal training as architects,

but both had yearnings to return from England

to the land of their fathers with huge architectural schemes.

And Maddocks' scheme was particularly ambitious.

His grand plan, and with Maddocks, everything was grand,

was prompted by the 1801 Act of Union between the parliaments of Ireland and England

to create the United Kingdom.

And with increased travel between the two capitals,

what was needed was a fast route between Dublin and London.

And if you draw a straight line between the two cities,

it crosses the coast right here.

The trouble was that in Maddocks' day, "here" was nowhere.

The vast mile-wide estuary of the River Glaslyn

presented a major obstacle to his ambitions to build his road.

If he could bridge the estuary, the race for Dublin was in the bag.

Maddocks' solution was simple and brilliant.

He poured years of effort and boatloads of money into building an embankment,

which by 1812 provided him with his missing link.

Stage two, he secured the right to make the natural harbour of Porthdinllaen

on the Lleyn Peninsula the main port of departure for Dublin.

Maddocks was within a whisker of winning.

But in the great dash for Dublin, he was pipped at the post by another brilliant engineer,

and another seemingly impossible route.

It was a photo-finish, and we'll meet the winner further around the coast.

But there's a twist to the story of William Maddocks.

When he built The Cob, as the embankment became known,

he certainly managed to keep the sea out,

and inland, he reclaimed a huge area of good agricultural land.

Problem. He'd also effectively dammed the River Glaslyn,

and stopped all that lovely Snowdonia rainfall flowing out to sea.

The river changed its course and followed the embankment.

Solution? Fairly obvious really.

Maddocks built tidal sluice gates that kept the sea out at high tide

and allowed the river to flow out at low tide.

Result. The power of the river pouring through the sluice gates gouged out a perfect harbour.

And what was once a nowhere" was now to become a very vital somewhere.

Sadly, Maddocks didn't live to see the day when millions of tonnes of slate

poured into that little harbour from the quarries of Snowdonia.

Slate that went out to roof the world, from Buenos Aires to Western Australia.

Around the harbour grew the prosperous town of Porthmadog, named after William Alexander Maddocks.

There's a Welsh word, "hiraeth". It means a longing to be back in Wales.

It's a longing that seems to apply to wildlife as much as to people.

There's one creature that goes to extraordinary efforts and travels thousands of miles

to return to this particular stretch of the Welsh coast every year.

Our zoologist, Miranda, has been looking at the strange nomadic ways

of the world's largest marine reptile.

About 20 yards.

He's down below us, Col.

This is absolutely unbelievable.

That's got to be 6ft long, that thing, innit?

Got a jellyfish.

Leather-backed turtles aren't accidental visitors to our shores.

They're actually migrating here all the way from the Caribbean.

Leather-backed turtles lay their eggs on the beaches of the Caribbean,

but once they leave,

these leviathans disperse into the open ocean

in search of their favourite food - jellyfish.

New research has revealed that leather-backed turtles migrate vast distances

into the cooler seas of the North Atlantic where jellyfish are more abundant.

Some turtles even make it into British waters

and one of the best places to see them

is here in Tremadoc Bay in North Wales,

where Dr Jon Houghton has been unravelling this incredible story.

-There you go.

-OK, thank you.

I have to say, I was amazed

when I found out there were leather-backed turtles around the UK.

It's just an animal you just don't expect to see here.

You don't, not at all. A few years back, a fellow actually sat down

and collated all the records of the leather-backed turtles

and it turned out to be thousands of animals which had been seen.

That's when we started to think

these probably have got more to do with this than just freak occasional visitors.

This is probably the largest one that has even been seen.

From the tip of its nose down to its tail,

probably about nine and a half foot and 916 kgs.

That is a huge animal.

This one washed up just over the other side of the bay in Harlech in the late 80s.

-Really close by.

-Yeah.

But why are the turtles coming here to Tremadoc Bay?

What we hoped was that we could try and find the large aggregations of jellyfish

that we knew the turtles would be feeding on.

So they are coming here to feed off the jellyfish?

-And there are big numbers of jellyfish here.

-There's enormous numbers.

It's completely possible to have 50 million jellyfish.

In Tremadoc, it makes that 7,000-mile journey to us worth it,

cos when they get here they're going to get a very good feed.

These barrel jellyfish live around the west coast of the UK.

That they don't sting must be an added bonus for one of Jon's colleagues, Tom Boyle,

who's been studying the food-chain involving the jellyfish and the turtles.

That looks like a big one to me, but is that a fully grown one?

Um, no, that's actually middle size.

A large individual would be three times that size, so 90cm,

so you're talking about that size, a big bell.

So, they're huge animals.

And why is it that the jellyfish seem to congregate in these particular bays?

Um, there's a lot of nutrients in these bays because they have fresh-water input.

So, there's going to be a lot of nutrients for the plankton to feed on

and then the jellyfish feed on the plankton,

and hopefully a turtle will feed on the jellyfish.

They'll have to eat a lot of those to get the energy they need.

It's pretty much equivalent to a chocolate digestive.

For a turtle, it's heaven, really, to come here with all this food around.

Leather-backed turtles disperse into the vastness of the Atlantic ocean in their hunt for food.

And as many as 100 individuals may visit our coast each summer,

but sightings aren't that common.

Our best chance of seeing a turtle

is to take to the air to survey the whole of Tremadoc Bay.

These are absolutely great conditions which is good.

The sea is quite flat, there's good light,

so if there is anything down there we'll stand a good chance of seeing it tonight.

You also get a real sense of the vastness of the ocean from up here.

-It's not just the turtles you can see from up here. Can you see down there?

-Got you.

-Are those?

-Yep, that's them.

-We've got four or five jellyfish down there.

-Yeah.

-That's brilliant. They're huge.

-Oh, it's great to see, yeah.

Those ones could be three, four foot long.

In these bays when these blooms really take off,

you're talking millions and millions of jellyfish.

They can spread 20, 30 miles right down the coast and out to sea,

so an amazing number of animals.

We flew over the whole bay but didn't see a turtle, which was disappointing,

but I guess not that surprising, as the turtles are spread over a very wide area.

But they ARE here.

This is up in the bay here.

This is fantastic because you can see in that,

they're feeding on the jellyfish we've been looking for today.

-The really big ones.

-Yeah.

So the point is they're happy. They're not going, "Oh, my word,

-"I'm 5,000 miles off course, what on earth am I doing here?"

-Yeah.

They want to be here and are very well adapted to being here.

But they're still reptiles, that's the thing.

And for a reptile, being this far north is quite incredible.

So you're saying leather-backed turtles

are native to the UK, they're not just a tropical species,

we should get used to seeing them?

That's definitely one way of looking at it. I mean, they're seasonal migrants, they want to be here,

they're here year after year,

and they've been doing it for a very long time.

So they are as much a British and Irish species as anybody else's.

Today, the route along the south coast of the Lleyn Peninsula

is awash with thousands of people

who, like the jellyfish and turtles in turn, come here for a good time.

But their annual pilgrimage to strut their sails

was itself preceded for many hundreds of years

by travellers of a different sort,

on a spiritual journey to Bardsey Island.

To pilgrims, three visits to Bardsey Island was said to be the equivalent of a visit to Rome itself.

And tradition has it that here lie the bones of 20,000 saints who came here on their final pilgrimage.

It also has a curious claim to fame.

Because from July 30th to August the 2nd 1284,

Bardsey became the seat of power for all England and Wales,

when King Edward I, having just hammered the Welsh 1-0 at warfare,

came to make peace with his God.

History doesn't record whether or not he had any response.

Heading back inland, we follow the northern route of the pilgrims

towards the splendid castle town of Caernarfon.

The locals are quite proud of Caernarfon these days.

But 800 years ago, it was a different story.

Caernarfon Castle was yet another in the great choke chain of castles

that Edward I built around the coast of North Wales,

to bring the Welsh to heel.

In fact it had the opposite effect, and castles like this stoked the fires of Welsh resistance.

Hero or demon, what Edward I had recognised was that if you command the Menai Straits

between mainland Wales and Anglesey,

you dominate this coast strategically. But what if?

If only you could do what seemed impossible in Edward's era and build a bridge across the Straits?

A vital link could be made, economically and politically,

between London and Dublin via Holyhead.

And the great "dash for Dublin" race that started back in Porthmadog

would be won.

Hey, presto, there they are. Two of our most remarkable bridges -

the world's first major suspension bridge, and the world's first ever box-girder bridge.

But, like putting a man on the moon,

or the first ever heart-transplant, we take them too easily for granted,

because the Menai Straits are classed as,

"one of the most treacherous stretches of sea in the world".

Not my words. His! Nelson's.

Now what did HE know?

More the fool me, I've decided to find out for myself.

Alan Williams runs Plas Menai, the national water sport centre,

and he's agreed to help me brush up my kayaking skills.

But I soon get a taste of the power of this tidal race.

It's very deceptive, Alan, because the surface of the water looks flat calm,

but there's something rather dramatic happening underneath.

The tide has turned now and it's ebbing quite strongly.

This is such a strange pattern on the surface of the water.

It's almost as if there's up-wellings from deep down.

That's because of the tidal rapid.

There's lots of rocks in there, and it disturbs the water.

And we're just about to hit another swirly section.

They're like miniature whirlpools.

They are, yes. It'll just grab you, but don't worry about it.

-Good heavens!

-Just stay comfortable.

-It's cool.

-OK.

Wow, that got the adrenalin going!

The tide's not really built up to its full strength yet, so it gives you an idea of the effect.

Oh, it certainly does. Wow!

Phew, heart beating now!

Today the Menai equals bliss in boats for thousands of visitors.

But traditionally it was anything but fun.

It was a vital artery to military and commercial shipping,

and God help the mariner who sailed these waters not knowing their whirlpools,

eddies, hidden rocks and fearsome tides.

Having experienced for myself the way they just grab at your boat as though it were a piece of paper,

I have huge respect for those who sail the Straits.

But I have unbounded admiration for the ingenuity and sheer courage

of the man who first succeeded in building a bridge across them.

The year was 1826.

The man was Thomas Telford.

It was he who won the race for a route from London to Dublin,

crossing the inhospitable mountains of Snowdonia

before coming to a sudden juddering halt at the Menai Straits.

Telford decided to make his crossing at the narrowest place on the Strait.

It was where drovers had always taken their sheep and cattle across.

Trouble is it was also the most dangerous,

where the current was fastest, and where there were the greatest number of whirlpools.

To cap it all, the Admiralty insisted

that the bridge be 100ft high, so that warships could pass underneath.

This was Telford's solution.

Telford's suspension bridge was a marvel of his age,

and today it even appears on this new one pound coin.

And looking at it from this very famous viewpoint, you can see that it's a work of extraordinary beauty.

But it's also a creation of engineering brilliance.

What Telford did was to float huge chains out into the Menai,

haul them over two central towers and anchor them deep underground

on both sides of the Straits.

A road suspended underneath the chains could support enormous weight

and so the suspension bridge was born. Simple? Yes. Brilliant? Absolutely.

The irony is that no sooner had the bridge been built, than it was outmoded.

To find out why, I've met up with civil engineer, William Day,

who is responsible for the maintenance of the Menai's great bridges.

Why was this amazing new bridge suddenly not good enough for the job?

Basically, we'd just entered into the railway age,

so a bridge ideal for stagecoaches was definitely not the right thing for railway coaches.

They were just too heavy. So what was required was a radical, new solution,

and what was required to provide that solution

-was a radical engineer like Robert Stephenson.

-Son of George Stephenson?

Indeed. Famous for the Rocket and the Stockton and Darlington railway - the first commercial railway in the UK.

But it was actually almost a bridge too far even for Robert Stephenson.

Robert Stephenson didn't just inherit his dad's train set.

In fact, he surpassed him in his skill as a locomotive designer and structural engineer.

But building a bridge with a huge span, capable of carrying massive loads

over a 100 foot in the air, was almost unimaginably difficult.

This was Stephenson's solution to the problem of crossing the Straits.

Telford had taken the best position.

Stephenson was left with the second best position.

But what we're looking at isn't the bridge as Stephenson built it.

No, that, unfortunately, was lost in 1970 to the fire.

Burning your bridges has always been bad news.

And with the rail link to Holyhead severed,

Anglesey was threatened economically, and so the bridge was given a massive facelift.

Fortunately, though, some of the structure of Stephenson's original Britannia Bridge still remains.

What have we got up here, William?

We've got one of the best kept secrets of the bridge.

Four lions, one on each corner.

They are magnificent.

The irony is that those lions can't be seen

by train travellers any more, or by people travelling on the road.

Indeed. They were visible many, many years ago.

But not as the bridge is now.

But the pedestal on which the lions lie sadly unseen,

outdoes anything in Trafalgar Square.

It's a massive structure, William. I feel completely dwarfed.

Very precisely made.

Look how tight the joints are.

But to see something really spectacular, you need to come in here.

-It's very dark isn't it?

-It is rather, we do have some lights.

Good heavens! It's like a cathedral.

You come in from the outside thinking it's a solid structure, but it's completely hollow.

I still can't get my head around what we're looking at.

A beautiful arrangement of arches. Three arches running this way,

arches running the other,

-which spread the load from the railway down into the masonry.

-It's a bridge of secrets, isn't it?

It's beautiful, with these great tapering columns rising up into the void.

When I first looked at it, I was absolutely amazed.

It's the most unbelievable and beautiful piece of engineering -

all to make this structure light and get the railway up to that height.

Just how Stephenson achieved this wasn't just radical...

it was revolutionary.

This was Stephenson's bridge before the fire.

But what was so special about it?

What he wanted to create was something that was light and strong,

and he achieved this by something akin to a bird's wing - the bones in a bird's wing.

Tubular and cellular. And this is it.

Oh, wow.

The only part that now remains of the original Britannia Bridge, a great monument to the man.

-What's it made from?

-Wrought iron.

To actually build a large structure, you've got to join pieces together, so you ended up

with two million rivets, and you can see some of them here.

But this metal is so thin. How did it become rigid?

Basically, if you join plates together in this cellular form, it's very, very strong, and very stiff.

So that you've got a very, very rigid box.

Unlike a suspension bridge, this box would stay stiff even as the train went over.

Stephenson's tunnel in the sky was an audacious idea,

but four interconnected "box girders"

as they're called, each 144 metres in length, now had to be lifted 30 metres into the air.

Today, it would be difficult. In 1850, it was a logistical nightmare.

Each of the tubes weighed 1,500 tonnes, which even today would be considered a fairly hefty load.

What he did was to float the bridge sections out and dock them into the bottom of the towers.

You can see where the slots are.

And how do you go about lifting 1,500 tonnes from down here, 100ft in the air?

Basically, you jack it up.

Stephenson was the first to do it,

and they used probably the most powerful jacks available at that time.

They would then put masonry underneath,

reposition the jack, and move again.

So it was quite a slow process that would have taken quite a few days.

So out of the chaos of this construction site down below

arose an incredibly simple engineering structure?

Very simple, very elegant, and at that time, unique.

We still build box girders, and we still jack big bridges into place, so the process Stephenson started

150 years ago would still be regarded as a modern technique.

For decades, Robert Stephenson's rail crossing stole the thunder from Telford's suspension bridge.

Railways ruled the world and the Menai Straits.

Then, someone invented the motor car,

and the usefulness and the honour of the suspension bridge was restored.

Today, the beautiful old bridge wouldn't be able to cope on its own

with the volume of traffic that needs to cross to and fro from mainland Wales to Anglesey.

If it wasn't for the fire that destroyed the Britannia Bridge in 1970,

the planners could have faced a real headache.

Their creation of a dual purpose road and rail bridge

from the ashes of Stephenson's original creation

perpetuated a rail link from London to Dublin and avoided gridlock on Anglesey's roads.

But it is a real tragedy that we can no longer marvel

at Robert Stephenson's original design, one of the wonders of the engineering world...

the first box girder bridge.

However you decide to get to Anglesey,

do take the opportunity to take a stroll along at least a part

of Anglesey's brand new 125-mile coastal path,

most of it designated an Area Of Outstanding Natural Beauty.

Coming to Beaumaris, we near the end of the new Anglesey coastal path.

Unbelievably, before the Menai Bridges were built, people used to wait until low tide

and actually cross here from the mainland on foot.

Another particularly hairy crossing used to be the Conway Estuary.

The ferry was as unpredictable as the tides.

But here, too, we find a pigeon-pair of extraordinary bridges...

a mini Menai suspension bridge, courtesy of Mr Telford,

and a baby Britannia bridge, courtesy of Mr Stephenson.

Historian, Neil, is on the trail of another construction project in Conwy,

and a barely-heard-of hero who was to help change the tides of war.

60 years after the end of World War II, and hundreds of miles from the main theatres of war,

it's hard to believe that this quiet little town of Conwy

and a local unsung hero had a vital role to play in the D-Day landings at Normandy.

By 1942, the tides of war had begun to turn.

Britain had mastery of the air after the heroic battle of Britain, but the war was far from over.

What was needed was a full scale allied invasion to liberate France,

and the only option was an invasion by sea.

The challenge they would face was Hitler's Atlantic Wall.

The French coast was pretty much impregnable -

every inch was iron clad. Every port bristled with Nazi armour.

What was needed was an artificial coastline and floating harbours.

"Impossible", said the boffins.

But Winston Churchill was adamant.

Cometh the hour, cometh the man.

Hugh Iorys Hughes was a successful but unassuming civil engineer who, on 1st June 1942,

was contacted directly by Churchill's staff, asking him to develop a prototype

for an audacious scheme, randomly codenamed Mulberry Harbour.

Hughes decided to build his top-secret prototype

on his home ground here in Conwy, and local historian Mark Hughes -

no relation - has long been fascinated by Hugh Iorys Hughes.

They were huge.

6,000 tonnes, 200 feet long.

Each one?

-Each one.

-Cor!

And what was, basically, the design?

His prototype design was one of concrete caissons,

best described as being an upturned cup which could allow water to be let in.

When they were empty, they could be towed.

And when in position, the water would be added and then they would be sunk,

and these would be connected by roadways.

It was envisaged that the ships would moor alongside the concrete caissons,

and then supplies would move along the roadways to the shore.

So it's like a gigantic Lego set with some Meccano on it.

Yes, probably a jigsaw is closer to the truth.

The Mulberry Harbours, comprising an incredible ten miles of floating concrete sections,

took 45,000 men just six months to build, at secret locations all around the coast of the UK.

And from June to October 1944, they provided the crucial landing stage

off the Normandy coast for two million men, 500,000 vehicles and four million tonnes of supplies.

Conwy can be rightly proud of the part it played

in developing the crazy, brilliant idea of a travelling coastline - the Mulberry Harbour.

But we should all celebrate the role of Hugh Iorys Hughes,

whose crazy, brilliant idea it was in the first place.

After the war, he just went back to the day job and lived a quiet life.

He died in 1977, unsung and undecorated,

but he was one of the few who did so much for so many.

Llandudno. The "wish you were here" name on thousands of postcards,

and another tale of one man's ambition, vision and enterprise.

Lord Mostyn was a local landowner...

in fact he was pretty much the only local landowner.

There's little around here that didn't belong to him.

In 1849, Mostyn realised that the new coastal railway could carry

something rather more profitable than post and politicians...

holidaymakers. From the industrial heartlands of Liverpool, Manchester and Birmingham.

So Lord Mostyn started turning a sleepy backwater

into a Mediterranean paradise with a promenade and accommodation for 8,000 fun seekers.

Llandudno never looked back.

Towering above the town, and dominating the whole bay,

is a huge outcrop of limestone - the Great Orme.

The Great Orme. Odd word, "orme".

It's not Welsh, it's not English.

In fact, like so many place names around here...

Anglesey, Bardsey, Swansea, Skomer...

it comes from one of the region's earlier visitors - the Vikings.

Orme means serpent or dragon.

It's close to the English word worm. And you can imagine how,

as the Vikings approached from the sea,

the Great Orme must have looked like some formidable sea monster.

But somewhere on top of the Orme, our anthropologist, Alice, is looking for remains

left by people who came here long before the Vikings,

at least 4,000 years ago.

Over there on that headland is the Graig Lwyd axe factory,

a Stone Age axe factory

whose axes are found all over the UK and northern Europe.

And then one morning about 4,000 years ago, everybody wakes up and it's the Bronze Age.

So they put down the stone tools which they'd been busily making up to that point,

and they start making sophisticated bronze tools instead.

Or did they?

When we talk about the Stone Age, the Bronze Age, the Iron Age,

it's as though we're meant to think of these people as being fundamentally different.

That suddenly they forgot their skills, their trade roots, their beliefs. But one thing is clear...

something extraordinary DID happen around 4,000 years ago.

It's quite difficult to think about what a huge imaginative leap it must have been

to think that you can take a rock, heat it up, and get a metal out of it.

It's not just that, because if you take malachite - if you take copper ore, you get copper out -

but to make bronze, you've got to add tin as well,

and copper and tin aren't just found in any old rocks.

These people travel and trade.

They're getting their tin from probably Cornwall, 200 miles away.

For copper, they're coming here to the Great Orme -

the biggest prehistoric copper mine in the world.

Just a few years ago, vast underground caverns were discovered below the Orme's surface.

Just come and have a look at this.

Wow, that's amazing!

It's not a natural cave, this has all been...?

It's all been dug out by people.

It is absolutely massive.

My guide is Nick Jowett,

one of the handful of people who excavated the ancient mines.

This is what it was all about.

The green that we can see in the rock here is malachite.

Malachite is copper ore.

We don't find much of it, because they were so good at mining.

These are the bits they've discarded.

What was in this chamber must have been just phenomenal.

To give me a real sense of what Bronze - or should I say Copper Age mining was about -

Nick's kindly offered to take me where the public can't go.

There's an estimated five miles of tunnels down here,

each hand-dug in search of the miraculous green copper ore.

Nick has recently discovered a new tunnel that no-one has entered for 4,000 years.

Just as well he's an expert pot-holer and member of a cave rescue team.

I've just taken my helmet off so I can get through this hole.

I'm not looking forward to it.

It's really, really narrow.

It defies belief that people were doing that 4,500 years ago,

4,000 years ago, down these caves, down these tunnels.

That was a pretty narrow squeeze.

All I can say is, they must have really wanted that ore.

So over all the years that they were doing it, how much ore do you think they mined out?

Well, the estimate so far suggests

that perhaps somewhere around about 1,700 tonnes of copper metal

came out of this mine.

That quantity would be enough to make around about ten million metal axes.

-Oh, really.

-And that's just an incredible quantity.

-Yeah.

But in the days before dynamite,

what technology did the Bronze Age miners have to extract the ore to create tunnels

as well as the vast open cast mine up on the surface?

The answer lies firmly back in the Stone Age.

-This is a piece of a rib bone.

-Yeah.

We can clearly see if we look at the end, it's worn and rounded,

and that's the evidence we have that these have been used as tools.

My goodness. So that's been, that's been rounded by digging away...

-That's it.

-..at the soil here, the ground here.

So all of that was dug out using implements like this?

That's it.

Mining using metal tools would have been like using the family silver to dig the garden,

so stone hammers and bone picks filled the tool box.

But it's the sheer quantity of tools Nick and the team found that's staggering.

This is one of our store rooms where we keep some of the bones that we've found in the excavations.

We've found about 37,000.

-If you want to have a look at them.

-Oh, OK, lovely. Right.

37,000 fragments of bone tools.

I'm curious to know what they can tell us about the miners themselves.

It's rather small, this one,

but there's an idea that scapulae were used as shovels.

A nice sort of shovelly shape.

And if there's any human material here.

It's not quite right, the curve of that.

I can see a tooth in here.

This is the tooth of a pig.

Oh, I was excited for a minute there.

Most of these bone fragments are actually from cattle,

so domesticated species.

We've also got sheep and goats and things like that as well.

So we know that they're farmers.

We know that they're pretty organised in what they're doing.

They're getting a huge amount of ore out.

And we know what sort of tools they're using.

We know what sort of animals they had living around them.

Is there any evidence of the people themselves? Now, I actually got quite excited because...

there are some human bones.

This is a jaw, mandible.

Some of the teeth have dropped out of their sockets

and a few of them are here -

the canine, and the pre-molars there.

It's got a very jutting out chin, so probably male.

This bone here is a collar bone or clavicle.

Now, that's two human bone fragments among 37,000 fragments of animal bone.

The really odd thing is that you go in,

and it's like walking into a workshop where somebody's just put their tools down and gone.

But there's no evidence of the people themselves.

There's no evidence of settlements.

There's no burials.

So where these people came from and where they went to afterwards... Where have they gone?

There's a lot of mystery still to be explained in the Great Orme.

So let's examine the evidence so far.

I sent the human bones off for radio carbon dating.

The result, 1600-1680 BC, which places our man firmly in the Bronze Age.

Analysis of his tooth enamel shows he was born locally.

The quantity of animal bones shows he lived in a stable agricultural community

that produced enough food to allow a number of people to do specialist work -

mining - on a huge scale.

And latest research has also shown that at the time,

the Orme was entirely surrounded by sea.

So travel and trade must have taken place by boat.

So really the next question is where did all that ore go?

Where is it being taken off for processing?

Now I'm going to go and meet Dave Chapman, who I think might have the answer for me.

As a 12 year old boy, Dave Chapman discovered a Bronze Age axe head on the Orme.

This started a lifelong fascination with Bronze Age techniques,

and led him to another discovery of national importance.

There you go, Alice.

This is the earliest metal working site in Britain.

-The earliest in Britain?

-Yes, yes.

-Wow.

-We've got a radio carbon date from here.

-Fantastic.

-Is that some charcoal? I can see some blackness in the soil.

-Yes, it's a 1580 BC.

-Yes.

And there's a close association of that with some copper slides that we found.

-Right.

-And they are from the smelting of copper ore to actually make copper metal.

You're telling me this - the first smelting site in Britain,

but it just looks like a nondescript bit of the coastline.

This is one of the most interesting nondescript sites you can get.

We're fairly certain that the UK's earliest known smelting site was once far larger.

Unfortunately, it was blown to bits in 1872 to make way for a road around the Orme.

But why smelt the ore here on a cliff edge a mile away from the mine itself?

Again, boats must have been at the heart of the trade in copper.

And the Irish sea, the M25 of Bronze Age commerce,

would have been busy with traders, flocking here in search of the magical green rock.

Dave Chapman has been conducting experiments

to see how ground-up malachite ore mixed with charcoal

was turned into copper.

That's very, very hot indeed.

-Can I touch it? Is it cool?

-Yes, by all means, it's cool now.

-OK.

-Is that pure copper?

-Yes.

Oh, that's beautiful.

It really is a magical process.

-It is, isn't it?

-Yeah.

It does appear magical, but these people knew what they were doing.

What they practised was nearer to science than to alchemy,

and I firmly believe that the story of the Great Orme mines isn't just a story about copper...

it's a story about people, about human endeavour and imagination.

Looking back at what we've discovered, an extraordinary picture is emerging.

It's really odd to be up here on a rocky outcrop

on the northern most tip of Wales, pretty much deserted today -

occasionally tourists coming in -

but 4,000 years ago, this was at the centre of a revolution,

an industrial revolution.

And this was a new society, the beginning of a new age.

The last stage of our journey continues on Stephenson's original dash-for-Dublin route

along the North Wales coast, past the ever-popular holiday resorts of Colwyn Bay, Rhyl and Prestatyn.

OK, pub quiz.

What is the capital of Wales?

Not difficult, is it? Cardiff.

Correct. This is a bit more difficult.

What, according to tradition is the capital of North Wales?

Here's a clue. It's the proposed venue for the 2007 Welsh National Eisteddfod.

Not much of a clue, is it?

Well, believe it or not, the traditional capital of North Wales is not in Wales at all.

It's a city in England.

# You'll never walk... #

Liverpool.

Oh, what about that!

From Liverpool to the Scottish Borders, my own Premier League companions will be discovering

the constant ebb and flow of human endeavour and industry.

And an extraordinary legacy.

Incredible ancient footprints in the sand.

Unseen threats beneath the waves.

And life at the cutting edge of Roman civilisation.

And I'm heading over the Dee to England, and over the Mersey to Liverpool.

See you there.

Subtitles by BBC Broadcast - 2005

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