Aerial photographs show earthworks of a bivallate, oval enclosure measuring approx. 123m east/west by 87m north/south, sited on dunes to the north-east of Mawdlam some 100m south-west of the monument at Croes y Ddadl. The enclosure has a broad inner bank, with a substantial ditch outside, and a secondary line of defences beyond. The earthworks have a hummocky appearance because of the surrounding dunes and of several trackways crossing them.

The enclosure was identified by Derek Elliot of the National Assembly for Wales from Royal Air Force vertical aerial photographs (CPE UK 2081, frame 4061) taken on 19 May 1947, prior to the construction of the M4 motorway. This now crosses just to the west of the enclosure, but it is uncertain how well the earthworks are preserved in the present day. Given the proximity of St Mary Magdalen's Church at Mawdlem with its curvilinear churchyard to the south-west, and the scheduled remains of Kenfig castle and settlement to the north-west, the enclosure could be early medieval or medieval in date. However, it could equally be an Iron Age defended enclosure.

T. Driver, 21 November 2006