A cairn is situated on the flat summit of Mynydd-y-glog, to the north-west of a trigonometrical survey pillar.
The greater part of the cairn mass is composed of loose unsorted stones with some consolidation by heather and grass around its rim. The cairn measures 16m (N-S) by 13m with a maximum height of 1.75m. The interior of the mound has been disturbed by the construction of shelters, particularly on the east. A short length of (probably) modern walling projects from the south edge of the cairn.

David Leighton, RCAHMW, 15 March 2001