Silbury Hill stands out in the landscape like nothing else. The largest man-made mound in Europe, we encountered it as we left Avebury. You couldn’t miss it. That it was made around 2500BC is doubly impressive. It was dated by the broken antler picks left behind by its builders – that means it was built around the same time as Egypt’s pyramids. And to this day it remains a mystery.
It stopped me in my tracks so that despite the rain I just had to stop and grab a photo. One thing I found remarkable is that although I was probably close to a mile away (1.6km) on a road leading over an adjacent hill I saw an indent near the top which suggested that a previous top – now a terrace-like feature – would have placed the hill top at that time in direct line with the horizon line from where I was standing. That is some serious engineering and surveying!
It was long assumed to be a larger version of the burial barrows in the district – but no burial chamber has been found despite three tunnels being dug through its centre.
- The first tunnel was built in 1776 by a team of miners hired by the Duke of Northumberland and Colonel Drax. They sank a shaft from the top of the hill.
- Then came an Archeological Institute dig arranged by Dean Mereweather in 1849. This tunnel went in from the side.
- And finally, in 1968 the BBC and Cardiff University dug another tunnel close to the second one.
Assuming it was a burial chamber for a great chief, they were each chasing treasure – hopefully on an impressive scale. But to date none has been found.
What has been discovered is how it was built. First a layer of gravel covered in soil and surrounded by a ditch. The hill was raised several times, with each successive phase filling in the ditch and recutting in around the new base.
Today the base covers more than two hectares – 5 acres – and as the hill was enlarged, the soil was stabilised with sarsen boulders from the district incorporated into the soil.
Unfortunately, there is no public access to the site as it is unstable – in 2000 a portion collapsed into the first tunnel which had not been properly filled in.
But as a triumph of human ingenuity and tenacity to build something greater than themselves, the Silbury Hill is an impressive piece of work.