Caer Aber Pwll is the western-most of two adjacent promontory forts, which together comprise a Scheduled Ancient Monument. Both utilise the defensive potentials of the steep coastal cliffs, with Caer Aber Pwll being the larger and more heavily defended of the two. The second fort, Little Aber Pwll, is situated some 100m to the east, although this fort's complex of banks and ditches extend to within 20m of it in places.

Caer Aber Pwll 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. A second enclosure on the east, measuring about 48m by 34m, may be a fragment of an early enclosure, isolated by redevelopment, an annex, or a separate and later enclosure butting onto the primary work.

Sources include:
Driver, T. 2007. `Pembrokeshire, Historic Landscapes from the Air', RCAHMW, pg 100, Figure 150.

RCAHMW, February 2011.