The remains of what appears to be a neolithic long cairn are located in a sheltered valley on the east side of the Plynlimon uplands. Its setting is a raised terrace above the south bank of the Afon Biga, a tributary of the Clywedog. It now lies in a small clearing just inside the Hafren Forest. The cairn measures overall 17.5m long west-north-west by east-south-east. Wedge-shaped, it measures 10.5m wide at its south-east end where it is 1m high, and 6m wide at its north-west end where it is 0.75m high. There are no obvious traces of ditching around the cairn. The cairn has been severely damaged through the cutting of excavation trenches and pits in three distinct areas of the mound. At the centre a trench has been dug transversely across the mound measuring 2m-3m wide and 0.9m deep, and is so pronounced as to give the impression of a site consisting of two conjoined mounds. At the north-west end is a pit measuring 1.5m by 1m and 0.9m deep above a stony base. At the south-east end is another pit measuring 4m by 1.5m and 1m deep, upcast rubble dumped on its south side. No structural features are exposed. The cairn is free of trees but is densely overgrown with garasses, mosses and other light vegetation.
The site may have been disturbed during the same episodes of mound investigations that affected other mounds in this area during the nineteenth century.
Sources:
Cadw scheduling information (MG323)
Inventory of Montgomeryshire (1911), 171-2.

David Leighton, RCAHMW, 9 February 2017