On the S bank of a tributary of Nant Garw, 290m above O.D., are remains of a rectangular structure 7.0m NW-SE x 4.0m overall. Its banks of turf-packed limestone boulders are spread to 1.5m wide and 0.4m high and the N corner has been eroded by the stream. The interior is boulder strewn and there is a possible cross-wall 0.8m thick near the NW end.
