On Silbury Hill (Little Toller Monographs) By Adam Thorpe - Silbury Hill in Wiltshire has inspired and perplexed people for generations. Artists and poets have fathomed their deepest thoughts searching for the hill's hidden meanings, archaeologists have tunnelled through earth for fragments that prove its purpose. But for all this human endeavour, Silbury Hill remains a mystery. We do know it is the largest prehistoric mound in Europe. But was it once an island, moated by water?