The site consisted of an outer ring comprising fifty-five small split oak trunks forming a roughly circular enclosure around . Rather than being placed in individual holes, the timbers had been arranged around a circular construction trench. Their split sides faced inwards and their bark faced outwards (with one exception where the opposite is the case). One of the trunks on the south western side had a narrow Y fork in it, permitting access to the central area. Another post had been placed outside this entrance, which would have prevented anyone from seeing inside. The timbers were set in ground to a depth of from the contemporary surface although how far they originally extended upwards is not known. In the centre of the ring was a large inverted oak stump.