And even at the most iconic sites, there's more than meets the eye, You just need to be prepared to look a little closer.

I'm mary ann Ohata, I'm an anthropologist and author and today I'm exploring Stonehenge in Wiltshire.

It's a slight cared for by english heritage.

It's been studied for hundreds of years and thousands of visitors come to see it every year.

So surely there aren't that many secrets still to unearth.

Well, you'd be surprised in fact today, to start understanding Stonehenge.

I'm not even at the site itself.

I'm two miles away at another english heritage site.

Wood henge, mm hmm.

This is wood henge.

And over there is Durrington walls.

Wood henge was a timber monument and it comprises of six concentric circles of posts.

And each of these concrete posts marks a place where the archaeologists discovered a post hole.

Mm.

The timber posts have long rotted away, but the archaeologists could work out the size of them from the hole that was there.

And so each of these concrete posts perfectly represents the diameter of the timber that was once standing.

But what we don't know is what they look like above ground.

They reckon that some of them could have been almost nine m high, but we don't know whether they were carved or whether they still had their branches on them, whether they were strewn with textiles or putative animal sacrifice.

We also don't know whether they had some kind of linking structure between the posts.

We don't have all the details of what would Henge would have looked like.

But what is absolutely certain is that this place was very special indeed.

And it was constructed in 2500 BC.

The same time that the stones were being raised at Stonehenge.

Yeah.

There are a few details that you might notice at this site.

The first are the low remains of an earthwork that circles the whole of the monument.

There's a bank and then a ditch.

It's a lot lower than it would have been originally because this land used to be plowed and so it's flattened it slightly but it's an earthwork similar to the one that your spot around the stones at Stonehenge.

And then at the center of the monument is this care which marks the burial site of a three year old child.

The remains were discovered in an archaeological excavation that was conducted in the 1920s and since then the bones have been lost unfortunately.

So we can't do further analysis.

It means that we don't know exactly when the child died or why but it's possible that this was a human sacrifice or some other kind of special burial that gave this site even more significant.

Yeah.

On the other side of the road is Durrington walls which is looked after by the National Trust.

And it's another site of extraordinary significance.

Archaeologists have discovered the remains of a huge timber enclosure and inside the enclosure were dozens of small houses.

The houses date to the same period as the stones were being raised at Stonehenge.

And we don't know whether these houses were homes to the people who were building Stonehenge or whether they came there to use or worship the stones instead.

We also find the evidence of timber, circular monuments much like this one at wood henge.

There's even more intriguing evidence that comes out of Durrington walls because what you can see in the landscape over there is an absolutely enormous earthwork it carries on across this field.

And then on the other side of that road down there as well, it's another henge enclosure with a bank and then a ditch.

But this one is a super henge.

What you can see now is basically a tiny sliver of what was originally, there would have been bright white cut through to the chalk and it would have been much, much higher than the ditch would have been much, much deeper.

That earthwork was built after some of the houses had fallen into disrepair.

And so the archaeologists think that maybe that earthwork was constructed in order to memorialize what had already happened at this site.

Another intriguing piece of evidence are the animal remains found at Durrington walls over 38,000 bones from pigs and cattle have been discovered that were butchered and cooked basically on giant barbecues from isotope analysis of the bones, we know that some of those animals were raised in Wales and other animals were raised in northern Britain.

They must have come here on the hoof in order to be fresh meat.

And we don't know whether that means that there were complex trading networks across the whole of Britain at that time or whether people were coming here with their animals to use this site and perhaps use Stonehenge.

Here's a really cool detail when the remains of these animal meat feasts were thrown into the ground, there was still plenty of meat attached to the bones, which indicates that they could afford to throw meat away.

So it challenges all our preconceptions about what life in the Neolithic was like because we know that at least some people were eating very well so well.

In fact they could afford food waste.

So who was using these sites?

Who came here with their animals and who got to have a big old barbecue in Darrington walls It's anyone's guess.

Both wood henge and Darrington are aligned to the sunrise.

Wood henge isn't actually a perfect circle, it's a slight oval with the axis aligned east west and Durrington, archaeologists discovered an avenue that is perfectly aligned for midwinter sunrise.

If you follow that avenue down this hill you get to the river avon and if you follow the river avon you get to an avenue that leads you directly to Stonehenge.

Mhm I'm here at Stonehenge now with Susan greenie an english heritage archaeologist the season the size that we're decoding today are wood henge.

Stonehenge both bear the name henge.

What exactly is a henge?

Hentges a circular usually earthwork monument surrounding other things.

So sometimes stone circles, sometimes timber circles like you saw it would henge.

And we're actually stood now in the ditch of Stonehenge.

The henge of Stonehenge.

And is it right I've read that Stonehenge isn't actually a proper henge.

What does that mean?

Khenyeza built between about 3000 Bc and about 2500.

And this is a particularly early one and it's sometimes referred to as a proto henge.

And is because here we have a ditch with an outer small bank and an inner large banks.

We've got two banks and a ditch whereas in proper Hentges you just get an outer bank and a ditch.

So this is a kind of early version.

And how does this earthwork link with the obvious massive stone monument in the middle?

Well, it's much earlier.

So as I said it was probably built in around 3000 BC and at that time we just have the earthwork enclosure and then some pits just inside the bank which we call Aubrey holes now and those pits might have held stones or posts were not quite sure but they were also used for the place where people put cremated dead.

So there's a kind of 500 year history of Stonehenge which is basically playing out before they put the stones up in the middle of the circle.

And the thing about Stonehenge is it's constantly remodeled and remodeled isn't it?

For more than 1000 years.

That's right.

So over the late Neolithic and into the Bronze Age people are coming here and embellishing and adding bits and changing things around.

So we know that for example when the stones got put up first they were in a different formation a couple of 100 years afterwards they moved some of the smaller stones, the bluestones around.

So people were coming back here time and time again and and rebuilding and re modifying the monument.

Should we go and have a closer look?

Yeah, sure.

So this is one of the markers that were put in place to show where the Aubrey holes were and the Aubrey holes of this early stage of the monument, a big pit with human cremated remains in it.

Yeah, that's right.

So there was about me 2.5 across and there were 56 of them all the way around the bank of the henge.

And we think that they held uprights of some kind.

Some archaeologists think upright stones, possibly the bluestones.

Others think maybe timber posts, but they were certainly used for the burial of these cremated remains.

And what do we know about the people whose remains these are?

We know that there are men, women and Children of various ages and we know that they come from very different parts of southern Britain.

So perhaps they're being carried here small little bags of cremated remains and being placed here at Stonehenge.

Wow!

So Stonehenge starts off as a cemetery and it's not just for local people and it's like famous right from the beginning.

That's right.

Exactly.

People are coming here from quite long distances.

Let's go see what else we can find.

Susan, tell me about the stones.

So we've got two types of stones here at Stonehenge.

We've got the enormous ones which are sauce and stone, which is a really hard type of stone.

And this is the local stone.

These ones, although they're up to 30 tons each.

They were bought from a local area.

So about 15 miles away to the north of here.

How do we know actually where they're from?

Well, if you can see up on the stone here, there's some little cut out circles.

Yeah, that's the plug where some work was done.

So these stones actually fell down in 1797 and they were put back up right in 1958.

And when they did that they found a bit of a crack through this big one here.

And so they pinned it together with metal rods and when they pinned it together they took out a column of the stone, a stone rod in effect.

And recently, only in the last year we've been able to geologically analyze that and match it to some natural sar sins and we've been able to pinpoint where these arson stones come from on the marlborough downs a site called westwards.

And then these are the bluestones.

That's right.

These are the smaller stones, but as you can see there actually pretty large and these are the ones that were brought all the way from the Priscilla hills in southwest Wales.

So although they are smaller and lighter, they've been brought over huge long distances to be put up here at Stonehenge.

What do we know about them?

I mean, why were they brought here?

And and how do they fit into the monument?

It's really difficult to know why these particular stones were brought.

Priscilla hills must have been a place that was important.

These stones must have been important, something.

Perhaps they were put up in a stone circle in Wales first and then brought here later.

But they've been put up in several different places.

And in fact that where they stood down today is not where they've always stood at Stonehenge.

Come over here and I'll show you how we know that this stone here.

Can you see it's got this, this groove all the way down one side.

The bluestones didn't always stand in the current formation.

We've actually got some clues from some of the stones that they were worked and shaped into slots and grooves.

So we think they stood together as pairs and also some the lintels and I've got corresponding tenants on upright stones.

So little mini triathlons.

So we know that they stood in a previous formation here at Stonehenge in that setting.

And archaeologists have found that when they've been excavated they found this double bluestone arc, which is where the bluestones first stood in the middle of Stonehenge.

I love the idea that there's a kind of a missing mystery monument from Stonehenge itself.

It's just that at some point the ancestors decided to rearrange the bricks and build something else.

There's one other type of stone here at Stonehenge that isn't a blue stone or assassin.

It's something different entirely.

So, this stone is probably perhaps the most important stone on the site, that one.

That's it, but profoundly underwhelming one.

That's right, yeah, this is a different type of geology.

So this one is made of sandstone and it comes probably from the area of the brick and Beacon's in Wales.

So, somewhere in between here in the castle hills in Pembrokeshire and we call it the altar stone, why do you call it the altar stone?

I mean, immediately, I'm thinking a kind of druid like shamanic figure doing wild rituals and blood sacrifice.

Too many fantasy novels, maybe, maybe.

Yeah, we call it the altar stone because it stands right in the middle of the most special inner sanctum of Stonehenge, it's surrounded by the horseshoes and by the circles of stones and it's laid flat, It's sort of like an altar.

So that's why, you know, antiquities first gave it name, altar stone, it could have stood upright, but it's probably quite likely that it was flat and it is here, right at the middle of the stone.

So we don't know what kind of ceremonies took place here.

But it's clearly it was an important stone.

It's kind of frustrating that it's been squashed by these there the rest of the treeless on with this one, isn't it?

Yeah, that's right.

So this is falling over at some point in the past, we don't know when the these are this is the tallest trial.

It on on the site sits at the head of the horseshoe.

One half.

It has fallen towards us.

And actually this here is the little, you can still see the Hollows underneath where it would have slotted on top.

And that gives us a really good sense of how they were carving and shaping these joints so that the stones fitted together and you can see the tenant that's still on the top there.

And Stonehenge is described as a clean site.

Is that right?

Because you don't find animal remains, you don't find bits of pottery.

It kind of looks like it was kept special in some way that makes it so different to what we find during two malls and wood henge where there's animal bones everywhere and bits of pottery and all sorts of houses, all sorts of kind of life.

Yeah, it's a complete contrast.

So you've got the two sides of being occupied and built at the same time, but they're very very different uses and different perspectives.

So here it's kept clean, it's kept sacred.

Perhaps it's not suitable for everyday life and lots of rubbish and excitement.

So maybe it's a special sacred place.