There are three principal components to the Cerrig Duon complex: a stone circle, 18.5-17.5m in diameter, centred on SN85112060, comprising 20 stones, none higher than 0.6m high (NPRN 412996) ; a monolith, Maen Mawr, at SN85112063 (NPRN 412997); what is described as an avenue, comprising two lines of stones, the one to the west being 42m long with 17 stones c.0.15m high, whilst the eastern is 25m long with 12 almost imperceptible stones (NPRN 412999). This last feature is perhaps better understood as a pair of stone rows, possibly the survivors of a greater system, also involving two stones alinged on the long axis of Maen Mawr. A phase of clearance, represented by a group of possible clearance cairns to the north and south of the complex (NPRN 84489), may have denuded the site of further, ritually significant stones.

RCAHMW, February 2011