The most impressive megalithic monument in the world, which has come to be known as the ‘Avebury Complex‘, lies on a spur of the Middle Chalk running northwestwards from the main massif of the North Wiltshire Downs. Immediately to the west runs the river Kennet. The monument consists of an approximately circular bank with a ditch on its inner side enclosing a level area of 28½ acres. On the inner edge of the ditch stood a circle of standing stones. Inside the circle again stood two interior settings of standing stones, each consisting of a double concentric circle, that to the north having in its centre three stones forming the so-called ‘Cove’, and that to the south a monolith. There was one original entrance through the bank and across the ditch at the south, and to this entrance an avenue (usually called ‘The West Kennet Avenue’) consisting of a double line of standing stones placed in pairs, averaging 50 feet apart transversely, and at average longitudinal intervals of 80 feet, led for a distance of over a mile from two small concentric stone circles on Overton Hill, known as ‘The Sanctuary’.