A cluster of three building platforms is located on the south-west facing slopes of Cefn y Brithdir cut into rising ground just below the crest of the ridge, at altitudes of 415-420m OD.
From west to east:
SO1287303053: platform terrace measures 16m long (NE by SW) rising slightly for the final 2m above the terrace scarp. The terrace is 6m wide at its outer end and 5.2m at its upper (hood) end. It is cut into rising ground to a depth of 1m and built out to 1.2m high. The lower half of the terrace, where it projects from the hillslope, is flanked along its sides by low banks, prominent along the northern edge where the bank is 1.5m wide and 0.25m high, less distinct on the south edge. The uneven interior is overgrown with bracken and stony below the turf.
SO1289003052: the terrace of the central platform measures 11.5m long (NE-SW), its SW end embanked for a further 3m. At a distance of 3.5m from its upper end the terrace steps down 0.2m. The platform is narrow, only 3.5m wide at its outer end and 3m wide below the hood. The terrace is cut back 1m deep and built out 1m high. The interior is overgrown with rushes and bracken and is stony below shallow turf.
SO1291003039: the terrace measures 13.5m (NE-SW) before it rises slightly towards its outer end where its sides are slightly embanked. It is 5m wide at the hood, 4.5m wide at the opposite end. The interior is featureless, overgrown with rushes and bracken, and stony below the turf.

Additional sources:
OS Record Card SO10SW/22.
Glamorgan Inventory vol.III part ii (1982), p.31 (PH46-8).

David Leighton, RCAHMW, 12 February 2016