Visiting Avebury and Silbury Hill, the site of Neolithic Britons

Dollop of guesswork

If I find myself wondering how on earth Silbury Hill got here, then I’m far from alone. It seems that people have been coming here to ponder its provenance since the arrival of the Romans 2,000 years ago. The first tourists could only employ their imaginations – and a healthy dollop of guesswork – to try to solve Silbury’s riddle.

I, on the other hand, have Dr Jim Leary, director of the Archaeological Field School at the University of Reading, to help me get to the bottom of its mysteries.

“In some ways you can compare Silbury to the early Egyptian pyramids,” says Jim. “It is roughly contemporary and it is of a comparable height and volume.”

But there the comparisons end. While the pyramids were grand statements designed to achieve maximum impact, Silbury is a lot more self-effacing. “Sure, it’s big,” says Jim. “In fact, if you plonked it in the middle of Trafalgar Square it would reach three-quarters of the way up Nelson’s Column. But come and look at the place and you’ll soon notice that it’s surrounded by hills, almost hidden in the countryside. Whoever built Silbury wasn’t trying to achieve shock and awe.”

And whoever built Silbury didn’t do so in one go, throwing it up in a few short months before sitting back and admiring their work.

“Excavations have revealed that building Silbury was a process,” says Jim. “It contains lots of layers, and these were added, little and often, over many, many years. And that’s reflected in what’s contained within the hill. There are no grandiose burials of high-status individuals here, as is the case with the pyramids. Instead, the people who built this place seem to have deposited everyday items here such as stone and antlers.”

But why? To answer this question, Jim and I leave Silbury Hill behind and make the 10-minute walk to a site that’s of equal importance to historians of Neolithic Britain – Avebury henge monument (henges are circular areas enclosed by a bank or ditch, often featuring standing stones). Approaching the henge along an ancient avenue flanked by enormous sarsen megaliths is amazing enough in itself. Yet, when you reach the henge, a huge earthen bank containing three stone circles, it becomes more evident still why the 17th‑century antiquarian John Aubrey described Avebury as a cathedral to Stonehenge’s parish church.

“We are now looking at the largest stone circle in the world,” says Jim, as we stand atop the henge looking down at the sarsen megaliths. “We think that it was constructed at about the same time as Silbury, about 2,500 BC – and that the massive bank and ditch possibly predate the stones. As to why it’s here, we have to employ some educated guesswork.”

Avebury henge clearly wasn’t built for defensive purposes. If the intention was to repel external aggressors, the ditch would have been on the outside of the henge, whereas here it is on the inside. There’s clearly something else going on entirely.

“One theory has it that it was built to welcome outsiders in – the exact opposite, as it were, of the traditional defensive ditch,” says Jim. “Another, slightly more sinister theory proposes that it was actually designed to defend people outside from something dangerous or powerful on the inside of the henge. We’ll probably never know the true reason for these stones’ existence – but it seems likely they had a spiritual purpose.”

Massive undertaking

Whatever the reason the Neolithic inhabitants of Avebury chose to build the henge, there’s one thing we can be sure of: it was one hell of an undertaking.

“The stones here are absolutely massive – the largest must be almost 100 tonnes,” says Jim. “Many of them would have lain underground, so the people here would have had to probe them, excavate them and move them into position. The level of engineering required to achieve that was extraordinary.” And that achievement speaks volumes for the complexity of the society that produced Avebury henge. “If ever you needed proof that life in the Neolithic wasn’t nasty and brutish, come to Avebury,” says Jim. “The henge is a wonderful work of human ingenuity – one that would tax even modern people. Whoever produced it were clearly capable of complex geometric artwork laden with symbolism. Sure, they had different belief systems and technologies at their disposal, but in many ways they were very similar to you and me.”

But what led these people to produce monuments such as those at Avebury and Silbury when, as far as we know, they’d never done so before? To answer this question, we have to rewind the clock 1,500 years to 4,000 BC and the dawn of the Neolithic era in the British Isles. It was around this point that the residents of these islands forsook millennia of hunting and gathering and adopted farming and sedentary living.

“We’re still not entirely sure why Britons suddenly turned to agriculture,” says Jim. “Farming is a far more work-intensive way of life. Instead of moving around taking advantage of the environment’s larder, your whole existence is dependent on what one area can – or cannot – provide. In some ways, it was a counterintuitive move.”

Counterintuitive or not, the transition to farming utterly transformed the way Britons lived. By the end of the Neolithic, they were expert woodworkers, and employed tools such as antler picks and modified cows’ shoulder blades as shovels. They were eating domesticated cows and pigs – Jim says there is evidence for some communities feasting on two dozen pigs in one sitting. And, last but not least, they had developed a very strong connection to their surroundings.

That sense of ‘place’ could well be the key to the construction of Silbury and Avebury in the third millennia BC. Containing not just these two sites but also West Kennet Long Barrow (a Neolithic chambered tomb) and Stonehenge, these few square miles in Wiltshire are to Neolithic monuments what Rome and Athens are to classical architecture. Neolithic Britons evidently attached great significance to this particular area and, says Jim, whatever it was may have flowed from Wiltshire’s water.

“There’s a congregation of rivers and springs in this area – you’ve got, for example, the nearby Swallowhead Springs forming the start of the river Kennet, which is itself fed by a winterbourne (a stream that dries up in summer) running through Avebury.

Further downstream, people were depositing items such as axes in these waters from at least the Middle Stone Age – and the best explanation we’ve got for them doing so is that they attributed some sort of spiritual significance to them.”

And that spiritual significance, says Jim, may well have extended to the sarsen stones themselves. “In the Neolithic, this area would have been littered with sarsens. The early antiquarians described how you could walk from one settlement to another on such stones without touching the ground. Those stones would have provided the huge trilithons found at Stonehenge, and we’ve also found them in the core of Silbury Hill.

I think there’s every reason to believe that our ancestors regarded them as sacred.”

The end of an era

We don’t know how many people lived in the Avebury area in the Neolithic, nor can we be sure how much communication they had with other residents of the British Isles, though the fact that there are other henges dotted around the British Isles suggests that there was probably some.

What we do know is that around the time that the monuments at Avebury and Silbury appeared, the Neolithic was coming to an end. This period witnessed the rise of the Bell-Beakers, a cultural group (originating from continental Europe) who produced elaborate pottery vessels that they buried in their graves. As Britain’s first metal-workers, they ushered in the Bronze Age.

Soon after, it appears that Avebury was abandoned and may well have remained so for centuries. All that changed during the Roman occupation of Britain, when a Roman road and a cluster of buildings (possibly including a temple) appeared in the area.

But while the Romans ushered in a brief revival for Avebury, its fortunes were to take a plunge in the Middle Ages.

“In the 14th century, Avebury’s stones were subjected to a sustained attack,” says Jim. “Many of them were pulled down, broken up and used as material in buildings. The destruction has often been framed as an act of Christian vandalism against ancient symbols of paganism. I suspect, however, that the motivation might have been more prosaic. In an era when the price of wool was booming, people needed the land on which the stones stood to graze their sheep. They may have pulled the stones down for no other reason than they got in the way.”

Whatever the reason, the stones’ future hung in the balance until the 20th century when archaeologist Alexander Keiller – the heir to a mighty marmalade business – set about restoring them to their former glories. In that, he more than succeeded. Today, 350,000 visitors make the pilgrimage to Avebury stones and henge each year. It’s a fitting tribute to what is, alongside Silbury Hill, one of the most remarkable and enduringly enigmatic monuments in the British Isles.

Jim Leary is director of the Archaeological Field School at the University of Reading

This article was first published in the November 2016 issue of BBC History Magazine