Silbury Hill is located close to Avebury, Wiltshire. It is a Neolithic man-made chalk mound and considered part of the Avebury complex.
The mound is 131ft high and is the tallest in Europe. The reason Silbury Hill was constructed about 4,750 years ago is still debated but its structure is built from chalk and clay from the surrounding area. A small mound was built first and then enlarged at a later date.
The top originally had a rounded profile, but it was flattened in the mediaeval period to provide a base for a building.
In March 2007, English Heritage announced that a Roman village the size of 24 football pitches had been found at the foot of Silbury Hill.