The most famous feature is the Great Circle, the second largest stone circle in Britain (after Avebury). The stone circle is in diameter and probably consisted of 30 stones, of which 27 survive today. It was recorded by both John Aubrey in 1664 and William Stukeley in 1776. The Great Circle probably was surrounded by the ditch (approximately outer diameter — now filled in) of a henge. The North East Circle is in diameter and probably consisted of 10 or more stones, of which 8 survive today. The South West Circle is in diameter, and has 12 stones surviving today. An avenue extends to the northeast of the Great Circle towards the River Chew and a second avenue meets it from the north eastern stone circle.