A ring cairn is located on a natural shelf on the south-east facing side of Twyn-y-glog.
It measures 6.2m (E-W) by 5.1m within a stony bank 3m wide on the north (2m wide elsewhere) and rising to 0.4m high above the exterior and 0.25m above the stone-free interior. There is no visible entrance. Its overall diameter is 10m.

David Leighton, RCAHMW, 7 August 2008