Rising to almost 40 metres high and measuring 160 metres around, Silbury Hill dominates an otherwise flat landscape. At roughly 4,600 years old, it’s the same age as the pyramids of Giza – though arguably even more mysterious. While there are burials near the Egyptian structures, excavations have found no such items around Silbury, nor any other explanation for its use.
Despite this sense of the unknown, the form still has a surreal effect on the green Wiltshire field it sits on. With no other high landforms to compete with, it stands alone against a backdrop of empty sky, while its even and rounded sides create few shadows, and appear to absorb all the light in the area. It absorbs attention too. On the nearby A4, drivers drop to a noticeably slower speed as this domineering feature looms into view.
One thing is for sure – the hill represents a feat of extraordinary human labour. ‘All of it would have been dug by hand, shovels, and pickaxes made from deer antlers,’ says archaeology writer, Mary-Ann Ochota, who penned this Discovering Britain viewpoint. ‘It was built in the late Stone Age, at a time just before metal tools were introduced.’
Estimations have the hill taking four million man-hours to complete. ‘It wasn’t done all in one go,’ explains Ochota. ‘It was heightened gradually over a period of around 80 years.’ In fact, the hill began as a small one-metre pile of gravel, using material probably collected from a nearby stream. Then followed a mound of soil, then another half million tonnes of chalk to finish it off.
Less mysterious is where the chalk came from. A ditch surrounds the mound on all sides, significantly lower than the natural ground level. The workers would have quarried into the earth and piled the material on top. In fact, it may be that the quarry is the main event, and the hill just a distraction. ‘Perhaps the act of digging was more important than the mound itself,’ agrees Ochota. During wet spells, the ditch fills with water which reflects the hill shape. ‘When it floods, the hill looks like it’s floating on its own sea,’ she says. ‘We don’t know for sure, but it’s possible that the quarry was extended just for this.’ Whatever its original intention, it’s an effect that continues to captivate.
This was published in the September 2017 edition of Geographical magazine.