The site of Silbury Hill is a gigantic flat-topped earthwork, in Wiltshire, England, and it is in fact the largest prehistoric artificial mound in prehistoric Europe and one of the largest in the world. The mound, a member of the Avebury complex of late Neolithic/early Bronze Age monuments in Wiltshire, measures a staggering 37 meters high, built out of buried sarsen stones. It was built between ~2,400-2,000 BC.
Why the mound was built has remained a puzzle; it is located in one of the lowest parts of the surrounding Marlborough Downs. One would suppose that if sheer height was the aim, you would start from a higher elevation. Other possible functions have tapped into the ritual significance of the other parts of the Avebury complex—Windmill Hill, Avebury Circle, West Kennett and Beckhampton processional avenues. Sims among others, considers that the Avebury complex was a large astronomical observatory, for tracking the sun and the moon.
Archaeology at Silbury Mound
Three major excavations at the site have been conducted, beginning with the Duke of Northumberland in 1776. All of them expected to find rich burials or anything else in the interior except construction. the century, but none have identified burials or any other features in Silbury Hill except evidence of human-placed earthen construction and associated debris.
Sources
This glossary entry is a part of the About.com Guide to Megalithic Monuments and part of the Dictionary of Archaeology.
Blain, Jenny and Robert J. Wallis 2004 Sacred Sites, Contested Rites/Rights. Journal of Material Culture 9(3):237-261.
Sims, Lionel 2009 Entering, and returning from, the underworld: reconstituting Silbury Hill by combining a quantified landscape phenomenology with archaeoastronomy. Journal of the Royal Anthropological Institute 15:386-408.
Thorpe, R. S. and O. Williams-Thorpe 1991 The myth of long-distance megalith transport. Antiquity 65:64-73.
