Silbury Hill in Avebury, Wiltshire is the largest man-made mound in Europe, it compares in height and volume to the roughly contemporary Egyptian pyramids. Probably completed in around 2400 BC, it apparently contains no burial. Though mysteriously important in itself, its purpose and significance remain unknown. There is no access to the hill itself. It is part of the Avebury World Heritage Site. Stonehenge is 16 miles away.