Silbury Hill, Wiltshire, England
Reputedly the largest prehistoric man‐made mound in Europe. Its present shape is a truncated cone with a base area of 2.1 ha and a height of 40 m. The flat top is 30 m in diameter. The chalk to build this mound was quarried from a ditch which runs round the monument, but which is now partly silted up. It has been excavated on numerous occasions, but most recently under the direction of Richard Atkinson between 1968 and 1970, work sponsored by the BBC. These excavations revealed that the construction of the hill took place in three stages.
Silbury I (c.2600 bc) consisted of a flat circular area about 20 m across which was enclosed by a low wattle fence. In the centre was a clay mound covered in soil and turves until it reached the fence. Over this was more earth and stone to form a mound 36 m in diameter and 5.5 m high. Silbury II involved the enlargement of the first mound with chalk from the surrounding quarry to form a structure 73 m in diameter. In the final phase, Silbury III (?c.2200 bc), the mound was again extended to give a diameter of 160 m. The new mound seems to have been built in a series of stages producing the effect of a stepped cone. Each stage was constructed with a series of buttress‐like dumps of chalk contained within retaining walls. The total volume of chalk in the mound is estimated at 350 000 cubic metres. What the purpose of the monument was is not known, as no burial has ever been discovered within it. It is inter‐visible with parts of Avebury and a number of other contemporary sites in the area.
The top of the hill was occupied in medieval times, presumably because of its defensive potential.