0:00:36 > 0:00:41Although the peak of Snowdon itself is 20 miles in that direction,
0:00:41 > 0:00:44we're already in the Snowdonia National Park.
0:00:44 > 0:00:47And this is one of the best coastal views in Wales.
0:00:48 > 0:00:52Behind this watery foreground of the Mawddach Estuary,
0:00:52 > 0:00:55rises one of my favourite mountains in the United Kingdom -
0:00:55 > 0:00:59Cadair Idris, "the chair of Idris".
0:01:01 > 0:01:04Snowdonia has been a national park since 1951,
0:01:04 > 0:01:07and although it's usually thought of as a mountainous landscape,
0:01:07 > 0:01:11it actually includes 23 miles of stunning coastline.
0:01:12 > 0:01:16Take the train across the estuary, you'll be in Pwllheli in a jiffy.
0:01:16 > 0:01:19This is one journey I want to last.
0:01:19 > 0:01:25This bridge was built in 1867 to carry the railway line across the estuary,
0:01:25 > 0:01:29but walkers are allowed to cross it too...for a price!
0:01:29 > 0:01:31- Hello there.- Hello.
0:01:31 > 0:01:34- How are you today? - I'm good, thank you.- Good show.
0:01:34 > 0:01:40- How much is it, please, for one pedestrian, with a lightly loaded rucksack and umbrella?- 60p, sir.
0:01:40 > 0:01:42- Thank you.- Thank you very much.
0:01:42 > 0:01:4660, 80, £1, another one makes £2 and there's your ticket.
0:01:46 > 0:01:49Keep that if you're walking back this way. It'll act as a return.
0:01:49 > 0:01:53- I'm on a one-way journey!- Oh, never mind. Keep it as a souvenir!
0:01:53 > 0:01:56- Bye.- Bye-bye.
0:02:04 > 0:02:07It's only when you get across the bridge to Barmouth,
0:02:07 > 0:02:09and follow the coast to Harlech,
0:02:09 > 0:02:13that you begin to realise your 60p toll was the bargain of a lifetime.
0:02:16 > 0:02:19Here, there's room to relax, room to breath...
0:02:19 > 0:02:22and rooms for all.
0:02:22 > 0:02:27Harlech itself, like so many towns I want to visit in North Wales,
0:02:27 > 0:02:29is dominated by its castle.
0:02:29 > 0:02:33Begun in 1283, it was Edward I's little way of saying,
0:02:33 > 0:02:35"Thank you", to the Welsh for revolting.
0:02:35 > 0:02:39And it was one of 12 of his castles in Wales to be designed or fortified
0:02:39 > 0:02:44by his French master mason, Master James of St George.
0:02:44 > 0:02:47Just over the river is another extraordinary example
0:02:47 > 0:02:54of essentially foreign architecture that's taken to these hills - an entire Italianate village.
0:02:57 > 0:03:02The whole village of Portmeirion was the vision of one slightly eccentric architect -
0:03:02 > 0:03:05Sir Clough Williams-Ellis.
0:03:05 > 0:03:08And it occupied him for most of his life.
0:03:08 > 0:03:14He started building in 1925, and it still wasn't finished when he died in 1978.
0:03:16 > 0:03:19He wanted to prove that, as he put it,
0:03:19 > 0:03:24"The development of a naturally beautiful site need not lead to its defilement."
0:03:24 > 0:03:30Was he right? Well, the purist in me is absolutely outraged by the arrogance of a man
0:03:30 > 0:03:35who thought that his own imagination could enhance such a beautiful place.
0:03:35 > 0:03:40But the escapist in me is irresistibly enchanted.
0:03:42 > 0:03:48But a large number of the 240,000 or so visitors who come to Portmeirion every year,
0:03:48 > 0:03:50aren't coming solely in search of beauty.
0:03:51 > 0:03:54"I am not a number, I am a free man."
0:03:54 > 0:03:58And I suspect they're not the first person to have stood right here and said that.
0:03:58 > 0:04:01"I am not a number. I am a free man."
0:04:02 > 0:04:06Patrick McGoohan's protestations that he was a free man,
0:04:06 > 0:04:10and his unaccountable terror of a giant white bouncy ball,
0:04:10 > 0:04:14were central to the '60s cult television series, The Prisoner,
0:04:14 > 0:04:16which was filmed at Portmeirion.
0:04:16 > 0:04:19As Number Six, McGoohan's constant persecution by Number Two,
0:04:19 > 0:04:22his efforts to discover the true identity of Number One,
0:04:22 > 0:04:27and his weekly attempts to escape the village, kept viewers on the edge of their seats.
0:04:30 > 0:04:33Personally, I can't imagine why on earth
0:04:33 > 0:04:36anyone would want to escape from this little paradise.
0:04:36 > 0:04:41Could it be true to say, for once, that the set upstages the drama?
0:04:41 > 0:04:43Clough Williams-Ellis, creator of Portmeirion,
0:04:43 > 0:04:46called it, "A home for fallen buildings",
0:04:46 > 0:04:50because so much of it is constructed from bits salvaged from stately homes.
0:04:51 > 0:04:53This, for instance, is the gothic pavilion,
0:04:53 > 0:04:56cannibalised from a Welsh mansion.
0:04:56 > 0:05:01The pavilion's dedicated to a less well-known visionary from 100 years earlier,
0:05:01 > 0:05:05who also had a dramatic effect on this part of the coast -
0:05:05 > 0:05:08William Alexander Madocks.
0:05:15 > 0:05:17Barely a mile away, as the seagull flies,
0:05:17 > 0:05:22you step into an entire landscape forged by the imagination of William Madocks.
0:05:22 > 0:05:25And he had a number of things in common with his neighbour.
0:05:29 > 0:05:32Neither Clough Williams-Ellis nor William Madocks
0:05:32 > 0:05:37had any real formal training as architects. But both had yearnings to return from England
0:05:37 > 0:05:40to the land of their fathers with huge architectural schemes.
0:05:40 > 0:05:44And Madocks' scheme was particularly ambitious.
0:05:44 > 0:05:45His grand plan,
0:05:45 > 0:05:47and with Madocks anything was grand,
0:05:47 > 0:05:52was prompted by the 1801 Act of Union between the parliaments of Ireland and England,
0:05:52 > 0:05:54to create the United Kingdom.
0:05:54 > 0:05:59With increased travel between the two capitals, what was needed was a fast route
0:05:59 > 0:06:01between Dublin and London,
0:06:01 > 0:06:04and if you draw a straight line between the two cities,
0:06:04 > 0:06:08it crosses the coast right here.
0:06:11 > 0:06:15The trouble was that, in Madocks' day, "here" was nowhere.
0:06:15 > 0:06:18The vast, mile wide estuary of the River Glaslyn
0:06:18 > 0:06:22presented a major obstacle to his ambitions to build his road.
0:06:22 > 0:06:27If he could bridge the estuary, the race for Dublin was in the bag.
0:06:27 > 0:06:30Madocks' solution was simple and brilliant.
0:06:30 > 0:06:34He poured years of effort and boatloads of money into building an embankment,
0:06:34 > 0:06:37which, by 1812, provided him with his missing link.
0:06:37 > 0:06:40Stage two, he secured the right
0:06:40 > 0:06:43to make the natural harbour of Porthdinllaen on the Llyn Peninsula,
0:06:43 > 0:06:46the main port of departure for Dublin.
0:06:46 > 0:06:50Madocks was within a whisker of winning, but in the great dash for Dublin,
0:06:50 > 0:06:53he was pipped at the post by another brilliant engineer,
0:06:53 > 0:06:56and another seemingly impossible route.
0:06:56 > 0:07:00It was a photo finish and we'll meet the winner further around the coast.
0:07:00 > 0:07:04But there's a twist to the story of William Madocks.
0:07:04 > 0:07:08When he built the Cob, as the embankment became known,
0:07:08 > 0:07:10he certainly managed to keep the sea out.
0:07:10 > 0:07:14And inland, he reclaimed a huge area of good agricultural land.
0:07:14 > 0:07:18Problem - he'd also effectively dammed the River Glaslyn,
0:07:18 > 0:07:22and stopped all that lovely Snowdonia rainfall from flowing out to sea.
0:07:22 > 0:07:27The river changed its course and followed the embankment.
0:07:27 > 0:07:29Solution - fairly obvious really.
0:07:29 > 0:07:32Madocks built tidal sluice gates that kept the sea out at high tide
0:07:32 > 0:07:36and allowed the river to flow out at low tide.
0:07:36 > 0:07:40Result - the power of the river pouring through the sluice gates
0:07:40 > 0:07:42gouged out a perfect harbour.
0:07:42 > 0:07:48What was once a "nowhere", was now to become a very vital "somewhere".
0:07:48 > 0:07:50Sadly, Madocks didn't live to see the day
0:07:50 > 0:07:55when millions of tonnes of slate poured into that little harbour from the quarries of Snowdonia.
0:07:55 > 0:08:01Slate that went out to roof the world, from Buenos Aires to Western Australia.
0:08:01 > 0:08:05Around the harbour grew the prosperous town of Porthmadog,
0:08:05 > 0:08:09named after William Alexander Madocks.
0:08:09 > 0:08:14Heading back inland, we follow the northern route of the pilgrims,
0:08:14 > 0:08:17towards the splendid castle town of Caernarfon.
0:08:19 > 0:08:22The locals are quite proud of Caernarfon these days,
0:08:22 > 0:08:26but 800 years ago it was a different story.
0:08:26 > 0:08:31Caernarfon Castle was yet another in the great choke chain of castles
0:08:31 > 0:08:35that Edward I built around the coast of North Wales to bring the Welsh to heel.
0:08:35 > 0:08:38In fact, it had the opposite effect,
0:08:38 > 0:08:43and castles like this stoked the fires of Welsh resistance.
0:08:47 > 0:08:51Hero or demon, what Edward I had recognised was that
0:08:51 > 0:08:54if you command the Menai Straits between mainland Wales and Anglesey,
0:08:54 > 0:08:57you dominate this coast strategically.
0:08:57 > 0:08:59But, what if?
0:08:59 > 0:09:04If only you could do what seemed impossible in Edward's era and build a bridge across the straits,
0:09:04 > 0:09:07a vital link could be made, economically and politically,
0:09:07 > 0:09:09between London and Dublin via Holyhead.
0:09:09 > 0:09:13And the great dash for Dublin race, that started back in Porthmadog,
0:09:13 > 0:09:15would be won.
0:09:15 > 0:09:17Hey presto, there they are.
0:09:17 > 0:09:20Two of our most remarkable bridges,
0:09:20 > 0:09:23the world's first major suspension bridge
0:09:23 > 0:09:26and the world's first ever box girder bridge.
0:09:26 > 0:09:30But, like putting a man on the moon, or the first ever heart transplant,
0:09:30 > 0:09:32we take them too easily for granted,
0:09:32 > 0:09:34because the Menai Straits are classed as
0:09:34 > 0:09:38one of the most treacherous stretches of sea in the world.
0:09:38 > 0:09:40Not my words - his.
0:09:40 > 0:09:43Nelson's. Now, what did he know?!
0:09:45 > 0:09:47More the fool, me.
0:09:47 > 0:09:49I've decided to find out for myself.
0:09:55 > 0:09:59Alan Williams runs Plas Menai, the National Watersports Centre,
0:09:59 > 0:10:02and he's agreed to help me brush up my kayaking skills.
0:10:04 > 0:10:07I soon get a taste of the power of this tidal race.
0:10:07 > 0:10:10It's very deceptive, isn't it, Alan,
0:10:10 > 0:10:13- because the surface of the water looks flat calm?- Yeah.
0:10:13 > 0:10:19- There's something dramatic happening underneath.- The tides turn now and it's ebbing quite strongly.
0:10:19 > 0:10:22This is such a strange pattern on the surface of the water, isn't it?
0:10:22 > 0:10:26- As if there's upwellings from deep down.- That's because of the tidal rapid,
0:10:26 > 0:10:30there's lots of rocks in there, it just disturbs the water.
0:10:30 > 0:10:33And as you can see now, we're just about to hit another swirly section.
0:10:33 > 0:10:36- It's like miniature whirlpools. - They are, yes.
0:10:36 > 0:10:39- It'll just grab you, but don't worry about it...- Whoa, good heavens!
0:10:39 > 0:10:45- Just stay comfortable... Cool.- OK.
0:10:45 > 0:10:47Wow, that got the adrenaline going.
0:10:47 > 0:10:50The tide's not really built up to its full strength yet,
0:10:50 > 0:10:54- so it gives you an idea of the effects.- It certainly does. Wow.
0:10:54 > 0:10:57Whoo, got the heart beating now!
0:10:58 > 0:11:02Today, the Menai equals bliss in boats for thousands of visitors,
0:11:02 > 0:11:05but traditionally, it was anything but fun.
0:11:05 > 0:11:08It was a vital artery to military and commercial shipping.
0:11:08 > 0:11:10God help the man who sailed these waters
0:11:10 > 0:11:15not knowing their countless whirlpools, eddies, hidden rocks and fearsome tides.
0:11:15 > 0:11:21Having experienced for myself the way they just grab at your boat as though it were a piece of paper,
0:11:21 > 0:11:24I have huge respect for those who sail the straits.
0:11:24 > 0:11:27But I've unbounded admiration for the ingenuity and sheer courage
0:11:27 > 0:11:31of the man who first succeeded in building a bridge across them.
0:11:31 > 0:11:34The year was 1826.
0:11:34 > 0:11:37The man was Thomas Telford.
0:11:37 > 0:11:40It was he who won the race for a route from London to Dublin,
0:11:40 > 0:11:43crossing the inhospitable mountains of Snowdonia,
0:11:43 > 0:11:47before coming to a sudden, juddering halt at the Menai Straits.
0:11:47 > 0:11:52Telford decided to make his crossing at the narrowest place on the strait.
0:11:52 > 0:11:55It was where drovers had always taken their sheep and cattle across.
0:11:55 > 0:11:58Trouble is, it was also the most dangerous,
0:11:58 > 0:12:03where the current was fastest and where there were the greatest number of whirlpools.
0:12:03 > 0:12:08To cap it all, the admiralty insisted that the bridge be 100 foot high,
0:12:08 > 0:12:10so that warships could pass underneath.
0:12:10 > 0:12:13This was Telford's solution.
0:12:20 > 0:12:24Telford's suspension bridge was the marvel of its age.
0:12:24 > 0:12:28And today, it even appears on this new one pound coin.
0:12:28 > 0:12:31And looking at it from this very famous viewpoint,
0:12:31 > 0:12:35you can see that it's a work of extraordinary beauty.
0:12:35 > 0:12:38But it's also a creation of engineering brilliance.
0:12:38 > 0:12:43What Telford did was to float huge chains out into the Menai,
0:12:43 > 0:12:45haul them over two central towers,
0:12:45 > 0:12:48and anchor them deep underground on both sides of the straits.
0:12:48 > 0:12:53A road suspended underneath the chains was capable of supporting enormous weight,
0:12:53 > 0:12:55and so, the suspension bridge was born.
0:12:55 > 0:12:59Simple? Yes. Brilliant? Absolutely.
0:13:00 > 0:13:03The irony is, that no sooner had the bridge been built,
0:13:03 > 0:13:05than it was outmoded.
0:13:05 > 0:13:10To find out why, I've met up with civil engineer, William Day,
0:13:10 > 0:13:13who's responsible for the maintenance of the Menai's great bridges.
0:13:13 > 0:13:18Why was this amazing new bridge suddenly not good enough for the job?
0:13:18 > 0:13:21Basically, we've just entered into the railway age,
0:13:21 > 0:13:24so a bridge ideal for stagecoaches
0:13:24 > 0:13:27was definitely not the right thing for railway coaches,
0:13:27 > 0:13:28they were just too heavy.
0:13:28 > 0:13:31So what was required was a radical new solution.
0:13:31 > 0:13:35And what was required to provide that solution was a radical engineer
0:13:35 > 0:13:37- like Robert Stephenson. - Son of George Stephenson?
0:13:37 > 0:13:42Indeed. Famous for the Rocket and the Stockton to Darlington Railway,
0:13:42 > 0:13:44the first commercial railway in the UK.
0:13:44 > 0:13:48But, it was actually almost a bridge too far,
0:13:48 > 0:13:50even for Robert Stephenson.
0:13:50 > 0:13:54Robert Stephenson didn't just inherit his dad's train set.
0:13:54 > 0:13:59In fact, he surpassed him in his skill as a locomotive designer and structural engineer.
0:13:59 > 0:14:01But building a bridge with a huge span,
0:14:01 > 0:14:05capable of carrying massive loads over a hundred feet in the air,
0:14:05 > 0:14:07was almost unimaginably difficult.
0:14:07 > 0:14:12This was Stephenson's solution to the problem of crossing the straits.
0:14:12 > 0:14:17Telford had taken the best position, Stephenson was left with the second best position.
0:14:17 > 0:14:21But what we're looking at isn't the bridge that Stephenson built, is it?
0:14:21 > 0:14:24No, that unfortunately was lost in 1970 to the fire.
0:14:24 > 0:14:27Burning your bridges has always been bad news,
0:14:27 > 0:14:29and with the rail link to Holyhead severed,
0:14:29 > 0:14:34Anglesey was threatened economically, so the bridge was given a massive face-lift.
0:14:34 > 0:14:40Fortunately, though, some of the structure of Stephenson's original Britannia Bridge still remains.
0:14:40 > 0:14:43- What have we got up here, William? - Well, we've got...
0:14:43 > 0:14:46one of the best kept secrets of the bridge,
0:14:46 > 0:14:50- the four lions, one on each corner. - They are magnificent.
0:14:50 > 0:14:55The irony is that those lions can't be seen by train travellers anymore,
0:14:55 > 0:14:58- or by people travelling on the road above.- Indeed...
0:14:58 > 0:15:02They were visible many, many years ago, but not as the bridge is now.
0:15:02 > 0:15:06But the pedestal on which the lions lie sadly unseen
0:15:06 > 0:15:08outdoes anything in Trafalgar Square.
0:15:08 > 0:15:12It's a massive structure, isn't it? I feel completely dwarfed.
0:15:12 > 0:15:15Very precisely made. Look how tight the joints are.
0:15:15 > 0:15:19To see something really spectacular, you need to come in here.
0:15:21 > 0:15:24- It's very dark, isn't it?- It is, rather. We do have some lights.
0:15:26 > 0:15:30Good heavens, it's like a cathedral!
0:15:30 > 0:15:33You come in from the outside thinking it's a solid structure,
0:15:33 > 0:15:36but it's completely hollow.
0:15:36 > 0:15:39I still can't get my head around what we're looking at.
0:15:39 > 0:15:41A beautiful arrangement of arches.
0:15:41 > 0:15:45Three arches run this way, arches running the other,
0:15:45 > 0:15:50which spread the load from the railway, down into the masonry.
0:15:50 > 0:15:55It's a bridge of secrets. It's beautiful, with these great tapering columns rising up into the void.
0:15:55 > 0:15:57When I first looked at it, I was absolutely amazed.
0:15:57 > 0:16:01Isn't it the most unbelievable and beautiful piece of engineering?
0:16:01 > 0:16:03All to make this structure light,
0:16:03 > 0:16:06and to get the railway up to that height.
0:16:08 > 0:16:11Just how Stephenson achieved this wasn't just radical,
0:16:11 > 0:16:13it was revolutionary.
0:16:18 > 0:16:21Now, this was Stephenson's bridge before the fire.
0:16:21 > 0:16:23But what was so special about it?
0:16:28 > 0:16:32What he wanted to create was something that was light and strong,
0:16:32 > 0:16:35and he achieved this by something akin to a bird's wing.
0:16:35 > 0:16:39The bones in a bird's wing, tubular and cellular.
0:16:39 > 0:16:42- And this is it.- Oh, wow.
0:16:42 > 0:16:45The only part that now remains of the original Britannia Bridge.
0:16:45 > 0:16:48Great monument to the man.
0:16:48 > 0:16:51- What's it made from?- Wrought iron.
0:16:51 > 0:16:55To actually build a large structure, you've got to join pieces together.
0:16:55 > 0:17:01So you ended up with two million rivets and you can see some of them here.
0:17:01 > 0:17:03But this metal is so thin. How did it become rigid?
0:17:03 > 0:17:07Basically, if you join plates together in this cellular form,
0:17:07 > 0:17:10it's very, very strong and very stiff.
0:17:10 > 0:17:13So that you've got a very, very rigid box.
0:17:13 > 0:17:14Unlike a suspension bridge,
0:17:14 > 0:17:20this box would stay stiff even as the train went over.
0:17:20 > 0:17:23Stephenson's tunnel in the sky was an audacious idea.
0:17:23 > 0:17:27But four interconnected box girders, as they're called,
0:17:27 > 0:17:32each 144 metres in length, now had to be lifted 30 metres into the air.
0:17:32 > 0:17:34Today, it would be difficult.
0:17:34 > 0:17:37In 1850, it was a logistical nightmare.
0:17:37 > 0:17:40Each of the tubes weighed 1,500 tonnes,
0:17:40 > 0:17:44which even today would be considered a fairly hefty load.
0:17:44 > 0:17:47And what he did, was to float the bridge sections out
0:17:47 > 0:17:50and dock them into the bottom of the towers, you can see the slots.
0:17:50 > 0:17:54And how do you go about lifting 1,500 tonnes from down here,
0:17:54 > 0:17:56100 foot in the air?
0:17:56 > 0:17:59Basically, you jack it up. Stephenson was the first to do it.
0:17:59 > 0:18:03And they used probably the most powerful jacks available at that time.
0:18:03 > 0:18:06They would then put masonry underneath,
0:18:06 > 0:18:09re-position the jack and move again.
0:18:09 > 0:18:14So, it was quite a slow process that would have taken quite a few days.
0:18:14 > 0:18:17So, out of the chaos of this construction site down below,
0:18:17 > 0:18:20arose an incredibly simple engineering structure.
0:18:20 > 0:18:24Very simple, very elegant and, at that time, unique.
0:18:24 > 0:18:29We still build box girders and we still jack big bridges into place.
0:18:29 > 0:18:34So that, the process Stephenson started 150 years ago,
0:18:34 > 0:18:37would still be regarded as a modern technique.
0:18:38 > 0:18:44For decades, Robert Stephenson's rail crossing stole the thunder from Telford's suspension bridge.
0:18:44 > 0:18:48Railways ruled the world and the Menai Straits.
0:18:48 > 0:18:52Then someone invented the motorcar.
0:18:52 > 0:18:57And the usefulness, and the honour, of the suspension bridge was restored.
0:18:57 > 0:19:01Today, the beautiful old bridge wouldn't be able to cope on its own
0:19:01 > 0:19:03with the volume of traffic that needs to cross to and fro
0:19:03 > 0:19:05from mainland Wales to Anglesey.
0:19:05 > 0:19:09If it wasn't for the fire that destroyed the Britannia Bridge in 1970,
0:19:09 > 0:19:12the planners could have faced a real headache.
0:19:12 > 0:19:17Their pragmatic creation of a dual-purpose road and rail bridge,
0:19:17 > 0:19:20from the ashes of Stephenson's original creation,
0:19:20 > 0:19:24perpetuated a rail link from London to Dublin,
0:19:24 > 0:19:27and avoided gridlock on Anglesey's roads.
0:19:29 > 0:19:34But it is a real tragedy that we can no longer marvel at Robert Stephenson's original design,
0:19:34 > 0:19:37one of the wonders of the engineering world,
0:19:37 > 0:19:41the first box girder bridge.
0:19:41 > 0:19:44E-mail subtitling@bbc.co.uk