Silbury Hill

Silbury Hill, a mile south of Avebury in Wiltshire, is one of Britain’s most enigmatic monuments. It is an artificial chalk mound, 31m in height and around 140m in diameter, built in a curve of the spring-fed River Kennet. It was built in the early Bronze Age, between 2400BC and 2300BC.

Tradition says it was the burial mound of King Sil (pronounced Zel) who was buried on horseback in golden armour. Other local lore says it was formed when the Devil dropped a sack of earth with which he had intended to bury Marlborough, foiled in his intent by the Avebury priests.

Despite eager exploration, no evidence of Sil or his gold has been found, but in the 18^th century, a body was found buried in the top of the mound, complete with a horse bit. This probably dates to the Medieval period when the top was levelled and fortified.

              Silbury from Waden Hill

Excavation has found Silbury to be far more complex than previously imagined. First, a gravel mound was raised, around a metre high and 10m in diameter. This was covered by turf and soil with a wooden retaining wall, then marsh-soil, chalk and gravel. The mound was now 5m high and 34m in diameter.

At least two other small mounds were incorporated into it. One contained yew berries, sloes, hazel shells and brambles: woodland soil which seems to have come from some distance away. The area around Silbury was open grassland grazed by farm animals. Sarsen stones were seeded through the mound ‘like raisins in a cake’.

The mound was soon expanded. Chalk was dug from a surrounding circular ditch and built over the mound. This ditch was 6m deep, 6m wide and 100m in diameter. As soon as it was dug, it was backfilled and redug further out, presumably linked to the new layer of chalk added to the mound. This happened five times.

Digging a ditch of those proportions with antler picks would take months of back-breaking labour, and raises questions of the mindset of these people. Why immediately destroy their achievement and start again? Assuming the labourers were working through free choice –there is no evidence of slavery at this time – they must have shared some common vision that lauded what to us seems entirely pointless work. Many monuments were continually remodelled, Stonehenge an obvious example, and it seems the process of construction was more important than the finished product. Perhaps the growing mound reflected the community’s growing spiritual or real-world prospects, so every remodelling was a celebration.

Silbury Hill is often thought to be unique, but another smaller mound at nearby Marlborough, long thought to be natural, has recently been proven to be human-made. Another mound, now entirely destroyed, was built in Marden Henge near Salisbury Plain. All three are situated in the curve of a river, on low-lying and probably very wet ground. Silbury is known for its springs, which flowed much more freely in the past, and would have filled the huge ditch with an unbroken sheen of water. The springwater is naturally warm and steams on a cold day, so the mound appears to be rising from the mist. Did the mounds represent the birth of the world, rising from the mists and the primeval waters, as features in so many mythologies? We shall probably never know.