The site is an oval enclosure measuring about 40m north-west by south-east, by 22m, defined by a rampart and ditch. It rests in the north-east angle of the defensive ramparts of Caerau hillfort (Nprn94517), having an entrance facing south-west towards St Mary's church (301612). It is thought to be an unrecorded castle belonging to the Bishops of Llandaf.
Possibly associated with Caerau Deserted Medieval Settlement (Nprn15250).
Sources:
RCAHMW 1991, Glamorgan Inventory vol. III part 1a 'The Earlier Castles', p.86-9.
RCAHMW air photos: 955174/43-7

J.Wiles 05.02.03