Can you uncover the mystery of Silbury Hill?

The huge mound dominating your view is Silbury Hill, built between 2470BC and 2350BC, at the end of the Neolithic (aka Late Stone Age).

It was built at a time just before metal tools were introduced to Britain. It means that the half a million tonnes of chalk and soil used to create Silbury were dug by hand, with wooden shovels and buckets, and pickaxes made from deer antlers. It’s estimated that it would have taken at least 4 MILLION hours of labour to construct.

However, modern excavations have shown that it wasn’t built in one go – the hill grew over several generations. The first mound was just a 1m pile of gravel, probably gathered from the nearby stream.  Years later, a mound of soil was built over the gravel. Pits and ditches were dug and refilled multiple times. It took at least 80 years for the mound to reach the size we see today - nearly 40m high and 160m in diameter.

We don’t know if the labourers who built it were forced to work, or whether they helped construct it willingly, perhaps as an act of devotion to the gods. Maybe the act of digging and building was more important than the mound itself.

Look at the field in front of you, notice how low it is, compared to the height of the road. The road is at the original level of the land surface. In the final stages of construction, the chalk and soil for the hill was quarried from the ground here, and a large ditch was dug around its base.

Look at the area of the field directly in front of you. If it’s been raining recently, you’ll see that it’s waterlogged. Even on a dry day, you can see that the grass here looks different to the rest of the field. This is where an additional rectangular extension to the ditch was dug out. We don’t know why. Perhaps it was to make the hill look like it was floating in its own sea when it flooded.

Notice how flat the top of the hill is. It may have been like this originally, allowing leaders or priests to gather on the summit, or it may have been modified much later, in early medieval times, and used for defence.

But why was Silbury Hill built in the first place? Despite centuries of study, it refuses to reveal its secrets.

The hill was constructed at a time when life was changing rapidly in Prehistoric Britain - communities were starting to bury people in individual graves rather than communal tombs. New types of pottery and the first, very special metal artefacts were introduced, marking the end of the Stone Age, and the start of the Bronze Age. Maybe the hill was a reaction to the new cultural practices being introduced in the region.

One of the best-known myths about Silbury is that it’s the last resting place of an ancient leader, King Sil, buried with his horse and golden chariot. Although no evidence for a burial has been found at Silbury, this myth could spring from an almost-but-not-quite forgotten folk memory of vast rituals commemorating a fallen ruler.

Other theories have focused on the shape of the hill. Perhaps it was built to be a feminine shape, the breast or curving hip of an Earth Mother Goddess, from whom fertility, good harvests and healthy livestock are secured. Many modern people also believe the hill is sacred – how does it make you feel?

Viewpoint written by Mary-Ann Ochota - author of Hidden Histories: A Spotter's Guide to the British Landscape