Episode 3 Britain's Ancient Capital: Secrets of Orkney

Stonehenge, on the plains of southern England.

Britain's most famous ancient monument.

But over 500 miles north,

new discoveries are being unearthed that challenge its supremacy.

How extraordinary!

And they're turning the Stone Age map of Britain on its head.

Was the centre of our ancient world

really in the remote islands of Orkney...

..a place cut off

by the fastest-flowing stretch of water in Europe?

We've joined forces with archaeologists

and hundreds of volunteers to investigate

how these far-flung islands may have forged Britain's

first common culture.

Oh, wow!

Andy, look at this.

So far, we've discovered this culture

is around 500 years older than originally thought.

It's way before Romans and Greeks.

It's before any of the pyramids.

And the stone circles here inspired Stonehenge.

It boggles the mind. It beggars belief.

Now we go on the hunt for the origin

of the very first stone circle.

We're going down, we're going to go investigate that,

and let's see what we find.

And we explore how this extraordinary society

came to a dramatic end.

There was a gathering,

and as many as 400 head of cattle were slaughtered.

Naturalist Chris Packham and I

search for clues on an abandoned island.

Maybe the people that left here

felt good about going to the mainland.

We find startling new evidence just outside the walls of the site.

Is it something totally new?

We've yet to see.

Archaeological adventurer Andy Torbet makes a breakthrough...

It's remarkable to think that no-one

has looked down this view for 3,500 years.

..and engineer Shini Somara

tests the sophistication of ancient technology.

This is working, I have to say, a lot better than I expected.

-Together...

-Wow.

..we investigate how this ancient society

which dominated Britain for 1,000 years

came to a sudden end.

Late summer in Orkney -

the last few weeks of an archaeological dig

that's overturning the ancient history of Britain.

The Ness of Brodgar -

a vast complex poised between two stone circles.

We're getting closer to understanding

the full history of this extraordinary place.

And a little set there.

Yeah. God.

This summer we've reached the bottom level of the site,

and we've made some remarkable discoveries.

We've set up base camp on the hill overlooking the Ness

to consider the latest evidence.

What we have got in now is the dates from, you know,

the deepest parts of the site.

What's fascinating is that

the buildings that are largely exposed at the moment

date to around 3000BC.

This date, this 3512BC date, means that 500 years before that,

there was already a complex of stone buildings on the Ness.

They were building there for such a long time.

And does that show that categorically

the Ness is older than the stuff happening down

in the South of England with Stonehenge?

The evidence is clearly building

that what was happening here at the Ness

predates the developments of this

Neolithic way of thinking further south.

This date is powerful support

for a brand-new theory,

that the Ness of Brodgar was

the centre of the stone circle cult

which swept Britain 5,000 years ago,

culminating in Stonehenge.

This summer, startling evidence has emerged

of what may have been the inspiration

for the very first stone circle.

How... How deep's the dive we're doing today?

Compared to what you're used to? Bloody shallow.

Seven metres, maybe. Eight.

Marine archaeologist Richard Bates has surveyed the shallow waters

near the Ness and discovered something intriguing.

So, Richard, where exactly are we?

Well, we're getting in towards

the middle of the Bay of Firth in here,

and so this is right at the heart of the area we've been surveying.

This location here has got probably the most interesting feature

in the whole of this bay.

Geophysical data shows a circular stone mound

below the waves that might once have been on dry land.

This is the main feature we're going to dive on.

This is the main mound itself.

You can see how perfectly circular it is, 40-metre diameter.

Nobody has ever seen anything like this

anywhere in the north of Scotland.

We're going down,

we're going to go investigate that, and let's see what we find.

-Fantastic. Looking forward to it.

-Yeah, let's get out there.

It's a prize worth diving for -

the answer to one of the great mysteries of British history...

..the origin of the stone circles.

6,000 years ago, the sea level around Orkney was lower,

so this mound might once have been above water.

Thousands of years of erosion

would've reduced the stone mound to a fraction

of its previous height.

If this was above water, thousands of years ago,

I can see people kind of latching onto this unusual natural feature.

The question is, though, do you know for a fact that it was above water?

Around this actual feature itself, we have yet to get that crucial core

that's going to answer that question, so, we...

You know, we want to go out there and do that.

Is that our next job then?

That's definitely the next job for us.

A core sample will prove one way or the other

whether the mound was once on dry land

and visible to the people of the Ness.

Back at the site,

the archaeologists have widened their search for the origins

of the culture which, we think, created the stone circle cult.

They have dug a trench through a grassy mound

50 metres outside the main complex.

They've revealed a Stone Age rubbish dump, or midden.

For archaeologists, middens are always treasure troves,

but dig director Nick Card thinks this one holds the promise

of something even more special.

At the end of last season, at the bottom of the mound,

we discovered some elements which could be a chambered tomb

that actually predates

the construction of the midden mound.

But... So, Neolithic, but...

-What, so, earlier than the rest of Brodgar or what?

-Possibly.

-Oh.

This structure could be one of the earliest on-site,

but if it's not a tomb, it could be something...

a completely new, unique form of structure,

the like of which we've never seen before.

Orkney is littered with chambered tombs.

One of the most spectacular is the Tomb of the Eagles,

discovered 50 years ago on South Ronaldsay.

If there is a tomb beneath here, it too might be intact.

One of the student volunteers has made a breakthrough.

Quite literally.

Right before lunch, at about, like, 12 noon, I think,

a couple of hours ago,

came up really delicately up underneath a little ledge

-and suddenly there was a hole.

-SHE LAUGHS

Right before I'm supposed to leave in a couple of days,

we find something really interesting,

so it's a little frustrating now.

Yeah, so it looks like there's a wall...

Ben Chan is the trench supervisor.

Cat just found, well, this void here,

which is about this deep,

and I can just about see inside the void.

It looks like there's a wall face there.

You know, it's a good starting point

to suggest that it is part of a pretty enormous structure

of some kind.

-It's pretty amazing.

-But that is peculiar.

-Yes.

So, I think, yeah, whoever's digging here better watch their footing.

A little bit Indiana Jones.

This could mean a massive structure,

the like of which we've never really seen before.

But what is it? Is it a chambered tomb?

Is it something totally new?

We've yet to see.

Chris is intrigued by one of

the other significant finds of the dig.

Cattle bones - thousands of them.

One thing that strikes me, Nick,

is that obviously there were a lot of cattle here.

If I were a Neolithic farmer,

keeping goats and sheep would be a lot easier.

The goats can go on quite steep slopes,

as long as they're well-drained.

They can eat almost anything, including quite rough grasses.

Why not have a mix of all of them and make more of the land?

Well, I think it's the status of cattle,

perhaps a reflection of the number of cattle you had,

that made a statement to other people -

-"This is how big I am."

-Mm.

So, I think the predominance of cattle can be a reflection

of other aspects of Neolithic society.

Cattle are a central part of Orcadian life, even today.

One find earlier this summer suggests that cattle,

for the people of the Ness,

were not only a source of sustenance, but also revered.

Oh, ho-ho!

Oh, my goodness. That is cattle bone.

These cattle bones were carefully placed

below one of the buttresses in the building

that may have been a kind of temple.

-Wow.

-HE LAUGHS

Yeah, I need a cup of tea now, definitely.

That... Oh, that's pretty special. Wow.

It looks like a ritual offering,

a vital piece of evidence helping to build a picture

of the complex belief system behind the mysterious stone circles.

In the Bay of Firth,

the hunt for the underwater stone circle is in its next phase.

There's a...a tantalising idea there

that this could've been the inspiration for all

these stone circles.

Andy and Richard are taking a core sample of the soil

around the stone mound to find out when it was submerged.

After 20 minutes of drilling, they've got it.

I think now we've got...we've had success,

and we've seen a decent core sample.

ANGLE GRINDER WHIRS

The sample they've collected gives them a cross-section

through thousands of years of history.

So, in here you can see it transitioning from this lake.

You see it getting reedy wetlands.

-See how it gets very dark in here?

-Yep.

Now you're on land. This is land surface.

So, we know at this point here, this is dry land,

and anything above it is dry land.

At that period in time,

-anyone walking around this landscape can see that rock feature?

-Yes.

The thing we need to find out is when is this point here.

So, radiocarbon is the best way, and so we'll get a slice of that,

get it bagged up, get it to the lab.

The soil analysis and radiocarbon dating

will establish when this mound was on dry land.

Well, I've just got back from an interesting dive

out in the Bay of Firth, where...

Bracing, was it?

It wasn't too bad, actually. It wasn't too bad.

But they've found what appears to be a natural stone circle,

which is quite unusual, but it's underwater.

It would be very traumatic to see your land,

upon which you depend, being inundated, encroached upon,

taken away by the sea.

And you might wonder,

"If that's gone, what's going to go next?"

And that might have inspired all sorts of behaviours

of people trying to intervene, you know,

and ask maybe the gods or the ancestors

to intercede on their behalf, and protect the land

upon which they lived and upon which they depended.

It would have been a really epic natural event

if that had happened, though.

So, it would have taken people by...

To see the waters rising around you during the course of a lifetime.

You know, when you're little the water's away out there.

By the time you're an old person, it's come all the way up,

and you think, "Where's that going to stop? Is it going to stop?"

What we are trying to do here is to figure out what people did.

Trying to figure out what they thought

is obviously a lot harder.

While we wait for the results of the dive,

there's another mystery to solve.

What we know for certain is that whatever the success

of the culture here and however long it lasted,

it came to an end, and the fascination is why?

Why did the people who'd been living a certain way for such a long time

find reasons to change so profoundly?

Recent evidence from the dig

has established that after it had flourished for 1,000 years,

the Ness came to a sudden end, around 2200BC -

the buildings abandoned, the temple structure dismantled.

To investigate, Andy and Shini are going to see

if evidence about the culture that followed can shed some light...

..and Chris and I are going to explore the reasons why

people abandon a whole way of life.

The lawn out there, the field...

-Yeah.

-It still looks very manicured and green, doesn't it?

-That'll be the cattle, keeping it down.

-Yeah.

Throughout its history, Orkney has seen many cultures rise and fall,

from the Iron Age to the Vikings.

Chris and I are spending the night

on one of the islands most recently deserted -

Swona, two miles off the western tip of South Ronaldsay.

God, imagine living out here.

-It's like you might as well be on a raft...

-I know.

-..at sea.

-Yeah.

It's so small.

I hadn't taken into account how small it is.

So, we're seeing it on probably one of the finest days of the year.

Yeah, most of the time the waves would be breaking over that.

They'd be breaking over that. We'd be lost in thick fog and rain.

The island had been inhabited since the Neolithic,

but the last inhabitants left in 1974,

abandoning it to the elements.

Perhaps their departure can help us understand

what happened at the Ness.

How many changes of clothing have you brought?

I need my party frock for tonight.

I've got big plans. I've got a portable glitter ball in here.

So, what do you reckon? That one looks the most habitable.

-The one in front of us?

-Yeah.

Yeah, it definitely does, doesn't it?

It feels quite strange approaching someone's abandoned home.

I wonder what's left in there.

Small hole in the roof,

but it looks in a better state of repair than that one.

Oh.

Oh!

Oh, look!

A hard hat, a saucepan,

two toilet rolls, a cardboard box and a brush.

What will future archaeologists

discern from that assemblage of objects, one wonders?

Would you believe it? Garibaldis, and I can't stand garibaldis.

Look at the seat! Look!

That's sail, a sailcloth.

-It looks like it's been knocked together from driftwood.

-Yeah.

The whole thing's got the look of some...

These are fish boxes, aren't they?

-It's been furnished with shipwreck!

-Yeah.

The thing is, Neil,

if we cast ourselves 4,000 years into the future,

imagine we're archaeologists here, what would survive?

-Well, the ceramic.

-The ceramic, the glass.

-Iron from the stove.

And the stove itself might not be intact,

but such a heavy piece of iron, I think there would be iron.

-I hate to say it.

-The plastic.

-The plastic will last...

-That will look in 4,000 years...

-It will look exactly the same.

-It's dry, isn't it?

-It's all solid.

-Yeah.

-This is dry enough to make camp.

-This'll do.

-I like the idea.

It's quite a sad place, quite poignant.

You know, you see, I don't feel that.

I see this as a...

as an optimistic place. Here nature is coming back.

It's going to have the last laugh here.

That's because you're on nature's side.

My sadness is on behalf of the little human civilisation here

that, for a combination of reasons, became too hard and was given up.

I think that's got a poignancy.

Maybe the people that left here,

-maybe they felt good about going over to the mainland...

-Mm.

..embracing new technologies, getting a TV, a washing machine.

That's the thing. I mean, you say that,

you know, the television, the washing machine.

The Neolithic was replaced, was supplanted,

by the technology of the Bronze Age.

Even if they resisted it at first,

they eventually went over to the bronze way,

and similarly here people had tried and tried and persisted,

but eventually the lure of another way of living.

This is one of those privileged opportunities, isn't it?

To get the chance to spend the night on an abandoned empty island.

Yeah, very much so.

This is a fabulous place.

It's kind of off the map.

Back at the Ness,

the team have borrowed an endoscope to look down into the void

they've just discovered.

It's not dark enough in there,

so the light's not really doing very much.

We can make out the wall, basically,

but I can see the wall anyway through the hole,

so it's not telling us very much new.

Goes about a metre in that direction.

About 1,200 plus.

This buried stone structure could be an ancient chamber tomb,

or something else altogether.

It's a slight puzzle at the moment because we would expect normally

for the interior face of a wall

to be well dressed, and this one is quite the opposite.

It feels quite roughly faced.

The bits that are not intended to be seen quite so much.

So, in some ways,

it feels like the building is a little bit inside out

and clearly we've got a lot left to understand what's going on here.

The jury's definitely still out on it.

And I know that Ben isn't wholly convinced yet,

but I still have an inkling that we do have the elements

of a chamber tomb.

After our night on the abandoned isle,

we're joined by wildlife cameraman Doug Allan.

-Hello, both.

-Hello.

He's accompanied by Cyril Annal,

the nephew of the last residents of Swona,

who spent his summer holidays here as a child.

Cyril can give me a first-hand account of life on the island

while Doug and Chris investigate the wildlife -

a unique herd of cattle.

-They look like normal cows.

-Yeah.

Yeah, they do. They look like perfectly normal cows.

They're Angus shorthorn cross.

Neolithic farmers domesticated the first cattle

from a wild breed known as aurochs.

The cattle on Swona were abandoned to their fate

when the last inhabitants left over 40 years ago.

Now they're returning to their natural state.

They haven't seen humans with any degree of regularity since 1974.

-'74 was the last...

-'74.

-So, how many generations of cow is that?

They think about ten.

Although they haven't changed genetically

or at least imperceptibly genetically,

their behaviour's changed,

and that's what we want to look at this morning.

-This way, Doug.

-OK.

I count 20 cows and calves

and then separate to the left there, there were the three bulls.

And of the cows and calves, there are at least four calves,

and they all look in very good condition, I've got to say.

So, they're not suffering the absence of human husbandry,

there's no doubt of that.

It's interesting to think that, probably,

since the end of the Neolithic,

this is as close to wild cows that there have been in the Orkneys.

Animals that have been unattended since '74.

I was just wondering, is this the size of herd

that the island can sustain?

Yeah, I think they have reached

-what we call their carrying capacity.

-Mm-hm.

Conditions out here are pretty harsh

and I should imagine that, therefore,

there's going to be quite a high first winter mortality

for these calves, and that will regulate the population.

I reckon we should try one more push in.

How far do you reckon?

Well, I think we can probably get another 40, 50 metres.

OK. I'm going to avoid looking at them.

-Yeah.

-Because I think if you look off to the side...

Yeah, I'm going to look down. You're right.

It's always a good technique.

The cattle on Swona have a fearsome reputation

for terrorising the few sailors or tourists who land here.

I expected these animals to run.

Instead of which, what they're doing is consolidate their position

around that group of calves.

So, they're doing a magnificent job of looking after those youngsters

in the face of what they see as a predatory threat.

I mean, this is primal behaviour.

This is what you see in musk ox and other wild bovids.

So, in the space of ten generations,

they've gone back to this inherited wild behaviour,

and that's absolutely brilliant.

People have lived on Swona since the time of the Ness.

At the turn of the 20th century,

it was a thriving fishing and farming community,

but Cyril's aunt and uncle were the last people to live here,

and they in turn left just over 40 years ago.

What happened by 1974 that the last occupant said,

"We don't need this place any more," was there a sadness?

There was a sadness and a disappointment

that the life wasn't continuing here as it had been for them.

So, the life elsewhere was just easier?

Yes, it was very much easier.

There was nothing wrong with the life here.

-There was nothing wrong with the life here.

-It just had its day.

Yes, it had its day.

What an amazing 24 hours.

It's perfect, in a way, because the time capsule in that house,

from the moment the human beings left,

nothing changed in that world,

-but yet in that world of the animals that you encountered...

-Yeah.

-..they've moved on.

-Yeah.

They've gone ten generations into the future and they're different.

Yeah, I know.

Oh, so good. This was our HG Wells moment.

-We've had a time machine.

-Yeah.

We've been back and we've come forward.

The whole way of life of Swona, remote and self-sufficient,

was rendered obsolete by the modern world.

When the Ness came to an end,

around 2200BC,

a whole way of life went with it.

Elaborate stone villages like Skara Brae

were replaced by individual homesteads.

The vast communal tombs like Maeshowe were sealed up.

The way the great stone circles were used changed as well.

The Ness of Brodgar,

which flourished for over 1,000 years, stood empty,

but we still don't know how or why.

A spectacular discovery last year on the island of Westray

could help us understand why this Neolithic culture disappeared.

All across Britain at this time,

a new way of life and technology emerged.

The Bronze Age.

-This is very pleasant.

-I wonder what it's going to be like.

Today, the settlement at the Links of Noltland

is only a few metres from the sea

in the dunes of an isolated beach.

Hiya.

Site director Hazel Moore is overseeing the excavation.

-It's big.

-It is, it is.

Well, it's more than we were expecting to find.

-So, this would all have been underground?

-Yes.

You have to imagine that we're actually inside a mound here.

We've taken the top off a mound and this is a subterranean room

and a passage that we found.

We weren't expecting to find anything quite so complicated,

so we're still finding our feet here as well.

The main floor area is entirely taken up by a water tank,

and the water tank is set above a natural spring,

so the tank is obviously the key feature in the building.

And what we can see from the mound around us here,

-it's made of burnt, cracked stone.

-Yeah.

So, what we think is, they're heating the stone

and using that to put into the tank to make steam.

So, what would the middle part have been used for?

What we're looking at is an underground sauna

or steam room.

-A sweat lodge.

-Gosh.

Hazel and her team have also discovered

a hidden underground passage.

What we have yet to find is where it goes to,

so that's our job for later on in the day.

-Mystery.

-Yes. That's our mission.

Andy is one of the world's most experienced cave divers

and is keen to get a look inside this tunnel.

I can see the passageway continues much as it is here, structurally,

but it bends round the left-hand side,

so I can't see any further than that bend.

However, unfortunately,

it's a bit too unstable at the moment

to put anyone in there, including me,

so we're going to send a robot instead.

Oh, looks interesting.

Yeah, it's a little remote control car.

I suppose we'll have some fun and games.

So, the plan is, we've got a camera here

on a little sort of gyroscope and a light.

So, I attach the rope to the back

just because I'm not 100% confident that it'll work in the sand.

I don't want to send it in and not get it back out.

-OK, that's a good idea.

-So, tie my rope on.

That is basically this TV screen for this camera.

The robot camera might be able to reveal

exactly where and how far this passage goes.

Lights on, cameras on. Yep, good. Right...

Right, let's see if this works.

While Andy gets his robot in gear,

I've also come along to join the Westray dig.

What does a sauna tell us about the Bronze Age in Orkney?

It's an interesting question.

Now, we haven't actually found a sauna before,

so this is our best guess,

but it's much more commonly found in a Scandinavian context...

..and it comes at a time when

there's increased trade with places like Shetland,

which is to the north of us here,

so it's possibly moving away from all the influences

that had been important in the Neolithic

and exploring a more northern part of the world.

So, Orkney had become a different place,

where in the Neolithic,

the influence and the focus was towards the south and Britain.

-Mm-hm.

-By the Bronze Age, it's turned through 180 degrees

and now looking and influencing, or being influenced by the north?

Mm-hm. Yes, I think so.

It was looking in a different direction, I think,

definitely, yeah.

This sauna is a far cry from the world of the Ness.

The Orcadians were still building in stone

but now they were also engineering with water,

and for what seems to be a very different purpose.

-Welcome to your home.

-This looks amazing.

Wow.

Shini is working out how the sauna functioned,

and with a team of locals is building a replica sauna.

A dry-stone waller, Gerry Wood, has constructed a metre-high base,

and a local weaver, Jan Hicks,

is making a willow frame for the roof.

The roof's starting to look really great

in terms of creating that dome shape,

and then on top, we hope that we can lay turf down.

It's like carpet, isn't it?

We don't know how long this is going to stay up,

but if it stays up long enough, it will, hopefully, grow together.

I'm going to put a third this side.

Shini's reconstruction is above ground,

but the principle is the same as the underground sauna.

It's not going to cave in.

-The willow is so supple, it'll bend but it won't snap.

-No.

-Last one coming, Shini.

-OK.

-Is that high enough?

-It's really sagging badly now.

Don't lean on it cos you're pushing some of the...

Yeah, I know. I've got a rake now, so I don't need to be on it.

-CRASHING

-Wait, get out, get out!

SHE GROANS

Yeah, I could see that happening from the inside.

-Yeah.

-Can we save this, or is it...?

We don't know that these things were covered with turf.

They could have been using animal skins.

So, do we have anything that resembles animal skins?

Maybe a hide. If we could find a tarpaulin...

-We haven't got a cow, but...

-We've got a tarpaulin there.

Why don't we try a tarpaulin?

It's lightweight and it saves us having to rebuild the whole wall.

Well done.

Andy too has run into a little local difficulty.

We might have a problem.

Didn't move an inch.

What we could do, if you've got any,

we could try and sort of manhandle planks up

into the tunnel and we push them along with the next plank

and try and create a little track for it to run along.

We've got planks here on site. Shall I go and get some?

-Yeah, I'll give you a hand.

-Grand.

I'll get this out and we'll get it sorted.

Right.

OK.

Right, we're at the top.

That's as far as she'll go.

-What can you see?

-It looks like it's blocked at this end.

You can see there's a big slab.

-It's a really fine-looking wall, though, isn't it?

-It is.

That's the first time anybody's seen that in thousands of years.

Is there any way we can kind of see the whole tunnel?

We've projected to where the passage goes to and we're digging down there

and the idea is to try and find the doorway from that end and then

-hopefully to clear the door.

-And then we'll be able to...

So, if you clear it from that end,

we should be able to see all the way through the tunnel?

That's right. Hopefully down to where we're stood now.

Along the beach,

Shini puts the final touches to her replica sauna.

That looks good.

It's not animal hides, but it really does look good.

I'm using this extra insulation turf round the edges

is going to seal the sides where the tarp joins the stones.

So, you know, cos we don't want too much steam loss.

That's one of the concerns.

Yeah. It's going to work a treat.

The real test will come tomorrow

when Shini tries out the sauna for the first time.

The lab has e-mailed me with their analysis of the core sample

from the dive in the Bay of Firth.

Andy is my first port of call.

-ON PHONE:

-'Hello.'

-Andy?

-'Yes.'

-It's Neil.

-'Oh, mate, how's things?'

-Not bad.

I've got the results back from the radiocarbon dates

of the underwater feature.

-'Oh, OK.'

-And, well, to cut a long story short,

it's been inundated by the water,

it's been a flooded feature by around 8,000 years

before the present.

'So, what do you think that means?'

Well, on the face of it,

it would appear that this idea that we had

that perhaps the presence of a large natural circular feature

in the landscape might have been an inspiration

for the henge monuments that come later...

-'Yeah.'

-..unravels a bit, because it would seem that

2,000 years before there were farmers here to be inspired,

that feature was already gone.

'It's disappointing.

'It would be great to think that that had started the whole

'stone circle tradition but, you know,

'from a scientific point of view,

'OK, we've proved that theory isn't correct

'but that's a step forward in the right direction.'

Can't quite make it fit at the moment.

So, the mystery of the inspiration for the stone circles remains,

but the hunt for an answer goes on.

There's only a week left before the dig

at the Ness of Brodgar must be covered over once more

to protect it from the incoming elements.

Every available volunteer is put to work.

Yeah, it's a very therapeutic thing to do, trowelling.

There's something very pleasing about it.

At the midden,

the small hole into the unknown void has now been carefully deepened.

It's a bit hard to see,

but this is actually a wall face

in here and you can count

at least seven courses of stonework making up that wall face

and then disappearing down, so I don't know how much deeper it is.

But what we didn't know

is that on this side,

so opposite that wall face,

is actually another massive upright slab of stone.

They've now revealed several large stones

within a few feet of each other.

Curiouser and curiouser.

I think all we can do is try and expose more of this,

but the intriguing thing is that all these separate elements,

some of them are lined but then, for instance,

this new slab of stone is over two metres long.

Just its location in relationship

to all these other structural elements

doesn't seem to kind of hang together at all.

It was already quite big and now it's really, really big.

So, yeah, it's extremely large and certainly bigger

than any we've got on this site.

This is just a hint that

this was a very unusual building, basically.

But that's one single block as far as we can see on either side...

-Right.

-..leaving a gap like that and at least that deep.

Every time we dig a bit of it,

it doesn't do what we want it to do

and we get more confused rather than less confused.

But that's the joy of archaeology, I suppose.

-Hazel.

-Hello! Hiya.

-Come in and have a look.

-Fantastic.

Back on Westray, they're about to make a breakthrough.

What do you think?

So, by my reckoning,

there should just be a plug of soil here that separates us,

and hopefully that's the last thing separating us from

the passage on the other side.

Have you been waiting for me?

Well, we've been holding ourself back

from pulling out this plug because we reckon

it can't be all that thick and there's probably a point in time

when it's going to just crumble away.

-That's the lintel.

-Certainly looks like it.

-Oh.

-Oh-ho.

There's a gap. Look at that. Right.

-Can you see that, Hazel?

-Look at that.

Can you see light coming through?

-Um, yeah, I can.

-Really? Oh, wow.

-Yeah.

Take a look. The sun's quite bright.

If you get right up close, you can see the entrance.

-Oh, yes.

-I'm pretty sure...

-It's actually quite a curve, isn't there?

-Yeah.

-Yeah.

-You can just see the edge.

The tunnel is revealed in all its glory,

and the way it's built may tell us

how this special place was actually used.

You can see all the way back.

You can literally see light at the end of the tunnel

just peaking in through the boards.

That curve is definitely

the same tunnel we were in yesterday.

It's remarkable to think that no-one has looked this view,

down this view, for 3,500 years.

The underground passage is both narrow and curved,

perhaps designed to intimidate or impress.

It suggests that access to the sauna

may have been limited to a select few,

or even reserved for sacred rituals.

What's it like for you to look down the tunnel?

We've been waiting a year now to actually see this,

so there's been a sense of anticipation

all the way and it's fantastic that it's intact.

We didn't know it would be, so this is just the icing on the cake.

-It's lovely.

-Yeah, it's beautiful.

Along the beach,

Shini's reconstruction shows just how effective

Bronze Age technology could be.

So, the first rock is in the tank

and we can hear it sizzling.

It's a test case, so hopefully it steams up.

Andy has volunteered to be a guinea pig.

-What do you think?

-I'm impressed.

-Yeah?

Yeah. It's really good.

This is working, I have to say - no offence -

but a lot better than I expected.

-Yeah?

-Yeah.

-I'm just glad it works.

You get a sense of what it would've been like

-in that complex on the hill.

-Yeah.

And they would've had a store of hot rocks,

so as these cool down, you just, you know,

top it up with more hot rocks.

And the thing is, the rocks,

I kind of thought, "One go and that will be them finished,"

but they're working again and again and again.

Yeah, they're actually very effective.

I might get you to build one of these in my back garden,

-if that's all right?

-SHE LAUGHS

For the people of Orkney,

this new technology may have offered both a more comfortable way

of living and a different spiritual life.

It's actually getting quite hot in here.

What we need is a plunge pool.

And there is one straight out the door.

Well done, Andy!

God, that must've been so cold.

That was bracing stuff. That was actually really nice.

Really nice.

Oh! Yeah, I could get used to this.

You know, Bronze Age sauna on the beach,

run down to a crystal-clear, beautiful, if a little chilly, sea.

I can see why they built it and why they built it here.

We now know more about what replaced the Neolithic way of life on Orkney,

but we still don't know why or how the Ness of Brodgar

came to an end when it did.

-How you doing?

-Hi, Neil. Welcome.

-Good to see you again.

Great to see you.

'Archaeologist Jane Downes is taking me to see an early settlement

'she discovered last year on the island of Sanday

'that may hold the answer to why these coastal communities

'are so susceptible to change.'

This is a very distinctive bit of landscape.

What's happening here?

It's caused by gravel accumulations

which have caused the spit to build up,

and the sand that you see has accumulated later.

Just coming up ahead actually is a little tuft of sand dune

-where we found the settlement.

-Oh, perfect.

So what was it that caught your eye?

First of all, we saw these stones sticking up,

and as we know from looking at

the other Neolithic and Bronze Age settlements, these upright stones...

Ah, right, these.

So, is that a hearth, that square setting there?

Yes, you're right. This is a hearth.

-These two in a row here?

-Yes.

-Right.

What could be a house shaped in an almost circular formation

running round, you're actually

sitting in the interior of it at the moment.

I found it hard at first to see

the outlines of this ancient homestead.

No wonder.

Jane tells me that this settlement was inundated by sand

thousands of years ago

and the people who lived here just moved away.

Around 2200BC, when activity at the Ness came to an end,

an increase in storminess and rising sea levels

would've made it more difficult to live by the sea.

A generally wetter climate

would have provided challenges for the lives

of the Neolithic farmers of Orkney.

Maybe it was this that prompted the changes to their way of life

and the abandonment of the Ness of Brodgar.

The archaeologists have also found evidence

of what happened at the very time the Ness came to an end.

A few summers ago, they uncovered thousands of burnt cattle bones

and piles of ash inside the main building, or temple,

which had then been carefully dismantled.

The destruction of the Ness and this great mass of cattle bones

found inside this temple may hold the final answer -

not to why the community disappeared, but how.

As many as 400 head of cattle were slaughtered.

And the shin bones from those animals were cooked

and smashed open and the marrow from within them was probably consumed.

It's like the wake,

the funeral feast to mark the death of this building.

The bones of these slaughtered cattle

might offer a unique insight into the community of the Ness

at the time of its end,

a clue as to what was really going on.

Archaeologist Ingrid Mainland is planning to analyse

the strontium in these cattle bones to reveal where they came from.

Well, the strontium, it comes...

It reflects the geology of the bedrock,

which is then incorporated into the soil of the plants,

and the animals eat the plants and that comes up into the body

of the animal, into the bones and into the teeth.

And depending on where you are in the country,

your strontium signatures will differ

depending on the geology of the bedrocks

that you're living within.

400 head of cattle.

You can't imagine Orkney having that many to spare...

-No.

-..that it could do away with that many adult animals

-all at one time.

-Exactly.

It represents quite a sacrifice for a community,

particularly if they did all come from Orkney.

You know, the animals represent your livelihood in the future,

so if you're culling that many across an area,

then that says something about the importance of the event.

We're sending some of the cattle teeth

to Durham University for isotope analysis.

We'll have to wait for the results.

Only a few days left before the dig comes to an end.

It's vital that every piece of data is recorded for scrutiny

across the long winter months when the dig is closed up

against the elements.

How do you do this on your own?

I always have an assistant taking photos.

HE LAUGHS

Shini is helping archaeologist Hugo Anderson-Whymark

to record this year's discoveries.

And we're going to do a row of photos.

We'll walk up twice.

So, we'll do one row of photos along this side of the trench

and we'll come back and do another row up this side.

And it will work out the relationship

of where your two cameras were and then it will create a 3-D model.

We'll try and spot familiarities from photo to photo,

-and based on that, it will stitch them together?

-Yeah.

What a fantastic piece of software for archaeology.

OK, so, I've downloaded the photos

and you're just beginning to see the outlines of the trench.

And the dense model, so all of those.

-Gosh.

-Some 5 million points calculated from...

-5 million?

-Yeah, from all those photographs.

So, can we now add this 3-D model to an overall 3-D model

that's been built?

Yeah, we have a model for the rest of the site

which I can show you here,

which is this view of all of the buildings on the site.

-That is incredible.

-Yeah.

Our new trench extends out

from the corner of this building down the slope this way.

This 3-D data could play an invaluable role

in uncovering the secrets of the site.

By making the stones appear smooth, details of carving,

which can be hard to see with the naked eye, may be revealed.

Back at the midden, they seem to be inching forward

to an extraordinary conclusion.

There are lots of questions,

not least of which, where the hell did these come from?

'They have found more of these large stones,

'or orthostats, within a few feet of each other.'

And what is the possible answer to that?

Well, we do wonder, were these originally standing stones?

Oh, heck.

After the disappointment

of the dates of the underwater circular feature,

the unearthing of these large stones,

like those found in standing circles,

could be leading us closer once again

to the origin of the stone circle cult.

So, once upon a time,

there was a stone circle involving these stones, maybe.

But if this is a stone circle, remnants of a stone circle,

that's been incorporated into the structure

and this structure predates the midden mound,

then what date does that make the stone circles?

Right.

Whatever the original function

of this stone structure beneath the midden,

it could mean people were building on the Ness

even earlier than 3500BC.

You're looking at the skeletal remains, in a way,

of a big - a very big - stone building.

That big long stone that's coming towards me

from the section of the trench,

and then there's another one going off in a straight line

and then it disappears

under the soil and there's...

It's a big square, or a big rectangle,

but only fragments of it are revealed at the moment,

but it's a monumental building.

This could be the first thing that was on the Ness of Brodgar,

some great big building that people were aware of and valued.

But even more difficult to get your head around

is the fact that these great long stones,

Nick reckons, might once have been standing stones.

They're now lying down on their sides

but once upon a time they were up like the Stones of Stenness.

So, maybe before even the great big building,

there was a stone circle here...

..so we're getting further and further back in time,

and this could be the reason for the Ness of Brodgar.

Get your head round that.

This extraordinary discovery

throws light on the origins of the Ness and its culture,

but we still don't know how it came to an end.

The analysis of the cattle bones may bring another clue.

Now, you know we took teeth from that fascinating deposit

of cattle bones,

and the strontium isotope was analysed.

Well, the results as they come back

seem to suggest that the cattle are not only all from Orkney

but they might all be from the same herd.

-SHE GASPS

-Isn't that amazing?

But I just like the idea that somebody had all that wealth.

It's almost like it was the royal herd

or the priesthood's herd that were used for this event

to close that building.

-I'll let you tell Nick, Jane.

-So, Nick...

-This is the isotope analysis.

-Wow.

-..the results are out.

-It's all there.

-Mm-hm.

For this to happen at that particular moment in time,

I think, is of huge significance

for our understanding of Neolithic economy.

Yes, major rethink required.

The isotope analysis reveals up to 400 cattle from one herd

were killed and the bones roasted in the flames of ritual bonfires.

It means that the abandonment of the Ness was carefully planned.

The people who lived here exploited one of their key resources, cattle,

in a way that was dramatic, even profligate.

Perhaps, as life across Orkney became more difficult,

they felt the need to turn to a new way of life.

These people faced the decision to move on,

just as the islanders of Swona did 40 years ago.

After this extraordinary period,

Orkney lost its influence over mainland Britain

and, from a southern viewpoint,

became a far-flung outpost.

But none of this can undermine the significance

of the thousand years when the culture of Orkney,

with the Ness of Brodgar at its heart,

seems to have dominated Britain.

It's the last day of the dig

and we're all looking back on what's been

an extraordinary summer.

We've discovered how the Orcadians could have moved the vast megaliths.

We've revealed how they could have crossed the Pentland Firth.

It's a funny thing that the only thing between us and the North Sea

is a bit of cow skin.

And we've found powerful evidence

that the people here inspired Stonehenge

and created Britain's first common culture.

It's as though in this season

we finally got back to page one of the Ness of Brodgar story.

I have read there it's eat at your own risk.

-Giles, eat it.

-Oh, God.

The archaeologists, volunteers, the team and I

celebrate with our own final feast.

-Edible.

-LAUGHTER

One, two, three.

A tasty Neolithic barbecue of roasted bone marrow.

One of the most exciting things has been sharing ideas and information

with the rest of the team.

You know, things that we've gathered from the archaeologists

and ideas that we've come up with ourselves.

Then you throw them onto the table

and other people chip in and it shapes and forms, I hope,

a better understanding of what

Neolithic man was doing in this place

5,500 years ago.

It really is beautiful here.

I mean, I've never been to Orkney and, you know,

the landscapes are...really kind of spark the imagination

of what life might have been like 5,000-plus years ago.

LAUGHTER

From my first sighting of the excavations,

I was convinced that the Ness of Brodgar

was uniquely significant,

and now with the evidence that we've been uncovering this summer,

the Ness of Brodgar should be a name that people know around the world.