The largest man made prehistoric mound in Europe, Silbury Hill sits by the side of the A4 between Calne and Marlborough and is about a mile (1.6 km) from the village of Avebury. It covers 5 1/4 acres and is built on a spur of natural clalk. It stands 139 feet (42.3 metres) high, its flat top is 100 feet (30.5 metres) wide with a base of 550 feet (167.7 metres) in diameter.

Excavations between 1968 and 1970 determined that the mound was built in four stages, together with a ditch, during the neolithic period, but a spacific purpose for the mound has never been determined.

Samuat Pepys wrote that it was called 'Selbury' after King Seall who it was said to be buried nearby. John Aubrey's interest in Avebury kindled interest in others, brought King Charles II to Silbury Hill in 1663.