The complex defences at Caer Aber Pwll (Caerau) define a simple promontory fort to the east and a more heavily defended promontory fort on the west, both utilising the defensive potentials of the steep coastal cliffs. The western fort contains at least one building platform and is enclosed by a complex of up to four banks and ditches thought to represent at least two periods of construction, of uncertain relation, extending over a roughly 172m front. The main, inturned, gateway can be made out on the far side of the earthworks.