The site originally consisted of 6 rings of wooden posts radiating out from a central point. They were enclosed within an earthen bank and ditch with a north east entrance as at Stonehenge.

It has conventionally been dated to about 2300-2000BC, making it contemporary with the building of the stone circle of Stonehenge. But excavations in the 1970s using new radio carbon dating techniques suggested that it could be more recent.