Caer Pwll-Glas is a prominently-sited bivallate hillfort, which occupies the south-eastern precipitous edge of a broadly triangular inland hill. Few defences were required on the south-east side where a single scarp sufficed, but on all other sides the fort is enclosed by two concentric banks and ditches, the inner measuring 17m by 3.5m overall and the outer 10m x 2m (Davies and Hogg, Cardiganshire County History 1994, 264). Davies and Hogg note a level berm between the lip of the inner ditch and the tail of the outer rampart. The entrance on the south-west is flanked by an impressive section of rock cut ditch. The interior is now disturbed by a conifer plantation and burrowing animals. Cambridge University aerial photographs from the 1960s (ADH 1 to 4, 13th June 1961) show the hillfort unencumbered by trees which had only recently been planted, and the possible existence of a circular inner enclosure which may represent an initial phase of construction or a pre-existing circular earthwork such as a burial mound.

From: Driver, T., 2005 The Hillforts of North Ceredigion: Architecture, Landscape Setting and Cultural Contexts. Unpublished PhD thesis, The University of Wales, Lampeter, Department of Archaeology and Anthropology.