A cairn is situated on a local summit towards the north-east end of Twyn-y-glog. It is composed of unsorted rubble piled up on outcrop giving overall dimensions of 10m (N-S) by 9m, height on the north 1.75m (0.75m on the south). At a distance of about 2.5m from the north edge of the cairn towards the centre is what appears to be an arc of inner structural walling which can be followed for a distance of about 5m around the mound. It may have been formed to contain the cairn which has since tumbled over it, or perhaps it reflects an early phase in the use of the site. No walling is visible elsewhere in the cairn.

David Leighton, RCAHMW, April 1992