Cadw SAM No.=GM003
Indications of a denuded and possibly dispersed cairn, 23m in diameter, enfold a hollow, c.4m in diameter, within which is set a twin chamber formed by a possible 12 orthostats, crowned by a massive capstone, c.4.0m by 3.0m by 2.2m, now partially frost shattered.
It is thought that the stone, the raising of which was one of, "the three mighty achievements of the Isle of Britain", is a natural boulder that has been undermined and underpinned to create the chambered structure.
(source OS 495 card; SS49SE18: RCAHMW Glam I. 1976 pt.1, 31-2)
RCAHMW AP94-CS 0664-5
RCAHMW AP945088/41, 43, 46