Silbury Hill

View of Silbury Hill from Wadden Hill

Silbury Hill is situated just off the A4 between Beckhampton and Marlborough. It stands prominently in the West Kennet valley close to the West Kennet Long Barrow; a Neolithic chambered tomb; the West Kennet Palisades; two concentric ditches which once held oak posts forming an enclosure; the Sanctuary with its six concentric rings, and Avebury stone circles. 

Silbury Hill is the largest prehistoric man made mound in Europe and is estimated to have taken four million man-hours to build. Its true purpose remains largely an enigma which archaeologists still theorize to this day.

Silbury Hill is 150m (492ft) in diameter and 36m (120ft) in height and 30m (98ft) across its summit. The base, which covers approximately 5acres is not a true circle but an octagonal construction in a spoked pattern rather like an open umbrella.

Radiocarbon dating from the last conservation/excavation in 2007/2008 by English Heritage, has confirmed that work started on Silbury around 2400BC give or take a generation, which puts it on the cusp of the stone age and bronze age. The conservation work by English Heritage and civil engineering company Shanka to ‘shore up’ Silbury after the summit imploded in 2000, gave archaeologists one last chance to excavate the monument before English Heritage sealed it for good in 2008.

How was Silbury built?
It is believed, through extensive archaeological investigation, that Silbury Hill was constructed in three phases. The first phase was a rudimentary mound of soil, gravel, flint and capped with clay. It measured approximately 10m (32ft) across and 1m (3ft) high. Many of the turf stacks appear to have been brought in from elsewhere which meant people must have carried material from far and wide to build the early phases of Silbury. The ‘laying down’ of this material may have been symbolic in expressing their own personal attachment to the project. This joint endeavour would seem to indicate a social ‘bonding’, a place where many would gather. This first phase became known as the ‘organic mound’ which would have been added to and added to many times until phase II saw the introduction of chalk.

Phase II comprising of soil, gravel, small sarsen stone, chalk and turves. This second mound was ringed by a series of wooden stakes poles and small sarsen stones which would indicate that it was used as an ‘enclosure’ of sorts. By now the mound had grown to approximately 5m (16ft) high and 35m (114ft) across. A huge ditch (there were two originally) was dug over 6m (20ft) deep and 100m (328ft) across, the spoils of which were used to build phase II and further additions of soil, sarsen, turves and chalk, each layer finished with a clay cap. Each phase was backfilled to allow further development. Silbury underwent generations of additions.

During the 2007/08 conservation project, significant grass samples were discovered at Phase II and were identified as those found on derelict wastelands where they would have taken around 15 years or so to establish. This would suggest there was a delay of some considerably time between phase II and phase III. The evidence shows that the mound was left, then cleared, then added to, then left, then cleared and added to and so on until phase III where huge amounts of chalk were added to give us the Silbury we see it today.

The final stage of phase III culminated in three steps or tiers that can be clearly seen today. Each step was constructed using fashioned chalk blocks which were backfilled then smoothed. When Silbury was finished it would have stood out as a gleaming white chalk edifice, a beacon in the landscape.
Radiocarbon dating by English Heritage, showed that it would have been possible for the whole project to have been completed in 100 years, though archaeologists working on the conservation felt it more likely to have taken considerably longer, as much as 400 years. They felt that Silbury was an ongoing project and reasoned it unlikely that somebody woke up one day and said “let’s build a 120ft high chalk hill.”

Inevitably, comparisons have been made in this final chapter of Silbury’s construction to those of the pyramids in Egypt. Indeed, Silbury’s 60 degree slope is comparable to the Great Pyramid at Giza. Let’s not forget that Silbury was being constructed at about the same time as the pyramids.

Silbury in Crisis
Silbury was first academically acknowledged in 1545 by John Leyland and later by William Camden in 1607. In 1663 John Aubrey in the company of Charles II and the Duke of York climbed to the top of the mound and in so doing brought Silbury to the attention of a much wider audience.

In 1720, William Stukeley visited Silbury and was the first person to prepare a number of sketches of the hill which are now held in the Wiltshire Heritage Museum, Devizes. Stukeley was of the opinion that Silbury was an elaborate viewing platform on which one could survey the ancient landscape below. It was during Stukeley‘s observations that a skeleton was unearthed at the summit which Stukeley mistakenly took to be the body of a ‘great king’, possibly King Sil. King Sil or Zel according to legend, was thought to be buried inside Silbury Hill along with a life-size statute of himself cast in solid gold sat astride golden horse.

This legend sparked the interest of treasure hunters. In 1776 Colonel Drax under the sponsorship of the Duke of Northumberland hired a team of Mendip miners to sink a shaft into the top of the hill to try to locate the treasure. Their efforts were to yield nothing of interest however. It was the Drax shaft that was to prove troublesome for Silbury in 2000 when the summit collapsed due to inadequate backfilling.

In 1849 the Central Committee of the Archaeological Institute under the supervision of Dean John Merewether dug a tunnel at ground level south-west. Again nothing of interest was discovered and certainly no treasure was found.

In 1922 the renown Egyptologist - Flinders Petrie, set his sights on Silbury. He saw Silbury in the same light as an Egyptian tomb and believed like Egyptian tombs, there would be a concealed entrance somewhere about the hill that would lead to a central burial chamber. He dug two trenches that revealed nothing but chalk rubble and a few antler picks, the latter Petrie regard with little interest and not worthy of further investigation. Today of course archaeologists would consider such finds invaluable for radiocarbon dating.

In 1968 the Merewether tunnel was reopened by Prof. Richard Atkinson in conjunction with the BBC who were filming a program for Chronicle in the hope of discovering Silbury’s hidden treasure. Nothing was found and the theory that Silbury was a giant tomb was finally abandoned. The excavation was not all in vain however, as a great deal of archaeology was discovered about Silbury’s construction.
 
As mentioned earlier, in 2000 the shaft dug by Colonel Drax collapsed opening up a 7m crater. Survey work carried out throughout 2001 by English Heritage discovered several other voids within the hill, again as a result of inadequate backfilling which included the tunnel dug by the BBC and various other botched attempts to excavate the mound. It was evident that Silbury’s integrity was at risk. Work to restore the monument commenced in 2007 with the reopening of Atkinson’s 1968 tunnel. Over 1460 tonnes of chalk were used to fill the voids and crater finally sealing Silbury for good. Amen to that

Why was Silbury Built?
Silbury has a habit of popping up in the landscape as you walk around the other ancient monuments in the area, this is surely not by chance.

Silbury stands like a giant raised platform in a sacred landscape - the Kennet valley. It’s surrounded by other sites that appear dedicated to ceremony and religion. Unlike Stonehenge, there is no evidence to suggest Silbury had any astronomical alignment. It wasn’t built originally as a fortification, although at some point during the Saxon occupation the summit (originally domed) was levelled to allow the construction of a defensive building. A huge 11th century post hole was discovered on top of the hill along with several armour piercing arrowheads lending more support to a fortification idea.

Restricted access
Access to ‘completed’ Silbury may have been restricted, as very little in the way of discarded animal bones such as pig have been found on its ascent. This would seem to indicate that only a small select group of people were allowed to ascend the monument and any feasting would have been confined at base level.

An acoustic experiment was undertaken using a variety of instruments from the prehistoric period. Bronze age wicklow pipes and iron age horns were blown by volunteers on top of the hill, whilst others members of the experiment were positioned at various points around the area of the hill to see if they could pick up what was happening on top. If Silbury was used for ceremony and access to the summit was restricted, then it would have been essential for those gathered at Silbury’s base to be able to hear what was going on above. The experiment was a success, as listeners confirmed they could hear the instruments up to half a mile away. This experiment is not conclusive proof that Silbury was ever used for religious ceremony however.

The Roman Occupation
During the1960s excavations, evidence was found linking Silbury to Roman occupation 2000 years after the hill was originally built. Prof Richard Atkinson found Roman pottery and a large amount of Roman coins and oyster shells from the south coast, a staple diet of the Romans apparently.
Until recently, evidence had suggested the Roman occupation at Silbury was nothing more than a small roadside (now the A4) tavern, but modern geophysical surveys have revealed an extensive patchwork of walls where buildings once stood. The area around Silbury was much grander than fist thought and in its shadow stood a small town.

Folklore
More fanciful theories for Silbury's construction have grown over the centuries, here are just a few:

1, As mentioned earlier, a burial site for King 'Sil'. A solid gold statue of the dead king sat astride a golden horse was thought to be buried with him. His ghost is said to ride around the foot of Silbury when there is a full moon.

2, A solar observatory or giant sun dial has been suggested which may have been used to measure the seasons of the year. Silbury casts a shadow across the level plain north to Avebury.

3, A huge fertility symbol dedicated to the earth goddess, so important to primitive farming communities at a time when crops and livestock depended on continued growth. The Swallowhead Spring which rises 450m (492yrds) south of the hill and is the source of the River Kennet is still thought to have health and fertility properties even now.

4, There is a tale involving the devil, who, on his way to bury the town of Marlborough under a sack of earth (folklore is a bit vague as to why the devil had it in for Marlborough) encountered the priests of Avebury. A much heated debate ensued, whereby the devil was forced to drop his sack of earth where he stood and hey presto! Silbury was born, lucky old Marlborough if you ask me.

5, Fairy Hills: from Irish folklore. Fairies, Elementals and Nature Spirits were believed to inhabit ancient manmade mounds just like Silbury. Some say that in the dead of night, at a time when you were allowed access to the hill, muffled sounds of revelry and gaiety could be heard coming from within the mound. Some have even described thousand of twinkling shimmering lights dancing about Silbury's summit. At this point, fairy folklore becomes a little darker. Should you find yourself enticed into a fairy mound, beware! For all is not what it seems. Although you will be welcomed and promptly invited to eat, drink and be merry by these ethereal entities, your eventual return and emergence back out into the real world will leave you horrified. Because, as you were innocently partying within the mound, outside, enchantment has dealt you a cruel blow, for one hundred years have elapsed and all those you loved and cherished are long dead.

6, A preparation for a landing stage for aliens spaceships, because it looks like a flying saucer! Give me strength. The lunatic fringe believe the builders of Silbury were first visited by aliens who showed them how to build it. Does that not insult the intelligence of our ancestors? This theory is purposely the last in my list, simply because it’s utter bollocks.

Times of change
Silbury sat at a pivotal time in prehistory when industrial and cultural change was taking place. Continental immigrants were settling in Britain and bringing with them a distinct new way of dealing with their dead and crucial new technologies, one of which was how to make bronze. There is no proof these people built Silbury but their impact on the Wessex area may well have influenced it. Stonehenge and Avebury were all under construction at this time, so is it possible that Silbury’s final stages were in direct competition for the biggest an most elaborate monument. Somethings never change

Silbury was the last great work of the Neolithic. Times were changing, society was changing, the last of the autocratic regimes which had in the past possessed the power to bring together vast groups of people to build these monuments were dwindling, Bronze Age Britain was moving away from giant earthworks, a new age was evolving.

Standing before Silbury Hill, something I have done on many occasions, you can’t help but marvel at what is quite simply a staggering feat of engineering. You may consider what drove ancient man to undertake such a massive project. Silbury was most definitely constructed for a purpose but we will probably never know precisely what. It remains a stupendous enigma, a masterpiece of human ingenuity and creative genius.

Please note: Silbury Hill is privately owned, access to the hill is strictly forbidden, this is to prevent anymore erosion and damage which has been inflicted by thousands of visitors over the years.

Thank you for complying to the English Heritage notices.