Avebury appears to be laid out on the basis of the Constellation of Taurus the Bull.
The Great Circle is the head, the inner circles represent the eyes and the two Avenues are the Horns.
The ancient Egyptians worshipped the Apis Bull which was depicted with a disc between its horns.
The disc was a Comet (Venus) which came terrifyingly close to Earth on a calendar period, between the Horns of Taurus – as at Avebury, where the ‘V’ star of Taurus appeared on the top of Silbury Hill, for which purpose the Mound was built.
The size of the Great Circle and ditch at Avebury is probably proportional to the proximity of the closeness of the Comet.
Avebury ceased to function around 1495 BC.