Silbury Hill

Archaeologists don't like to talk about it, but really instead of digging new sites we should be spending most of our time going back through the records and collections from digs that were done decades ago but never properly cataloged or published. I am convinced that the answers to many of our questions about the prehistoric past have already been dug up and are awaiting discovery in some museum basement. Or, more urgently, awaiting discovery in the mind of some aging amateur who may die before any professional plumbs his memories or sees his collection. But people become archaeologists because they want to dig, not because they want to spend years reading old excavation notes, so we quietly ignore this disappointing truth.

Case in point: the most important discovery in decades about Britain's enigmatic Silbury Hill has just been made in some letters written in the 18th century:

Letters that lay undiscovered in national archives for more than 230 years suggest that Silbury Hill, the enigmatic man-made mound that stands between Marlborough and Beckhampton, may have originally be constructed around some sort of totem pole.

Historians have uncovered in the British Library in London letters written in 1776 that describe a 40ft-high pole which once stood at the centre of Silbury Hill. Europe’s largest man-made mound. The letters detail an 18th century excavation into the centre of the man-made mound, where archaeologists discovered a long, thin cavity six inches wide and about 40ft deep.

A separate excavation found fragments of oak timber within the cavity leading historians to believe that the mound was built around the pole dating from around 2,400 BC.

David Dawson, director of the Wiltshire Heritage Museum in Devizes, said: “This is important, lost information dug out of the library, rather than through field work. “It tells us that in one of its earliest phases some kind of totem pole was erected on the mound, then subsequent additions to build the hill up were piled up around that timber.”

The 18th century letters, written from Edward Drax to Lord Rivers, described excavations Drax had supervised at Silbury Hill. He oversaw the digging of a vertical shaft from top to bottom that is sometimes claimed to be the work of the Duke of Northumberland.

Drax, a wealthy landowner who lived in Bath, had hired a team of miners to dig a shaft from the top of Silbury Hill, to the centre of the hill, 125 feet below To begin with the miners found little but chalk and pieces of deer antler, but 95 feet down - some 30 feet above where they expected the base of the mound to be – they stumbled upon a deep, narrow cavity.

The hole was six inches across but Drax noted: “We have already followed it already about 20 feet, we can plumb it about eleven feet more.” In his letter he wrote that “something now perished must have remained in this hole to keep it open”.