A group of house platforms is located on common land at 120m above OD on the south-west end of Cefn Drum.
The earthwork features, last visited by RCAHMW in 1961 and surveyed by OS in 1982, are as follows:
SN 60820401 (1): a curving bank, turf-covered, measuring 7m long (NW-SE) and 2m wide, 0.6m high on the S, 0.3m high on the N.
SN 60820403 (2): 20m N of (1), a rough platform 5m square cut into the hillside to a depth of 0.4m.
It seems likely that features 1 and 2 together constitute platform 'B' described by RCAHMW in the Glamorgan Inventory.
SN 60800405 (3): a vague cutting in the hillside, probably platform 'A' described in the above source.
SN 60840402 (4): described as a small turf-covered platform (2m square and 0.6m high) built out from the slope, this is perhaps the the clearance pile described by RCAHMW.
SN 60770404 (previously unnoted): a feature resembling a platform but which may be a disused level. Nearby on the south-west is a curvilinear bank about 18m long, averaging 2.5m wide and 0.4m high.

RCAHMW Glamorgan Inventory vol. 3(ii).
OS record cards SN60SW

David Leighton, RCAHMW, 5 December 2000