The defended enclosure at Pen-y-Gaer is a rectangular enclosure of about 38m, demarcated by a 3m thick rubble wall, which was faced with large orthostats. The remains of the entrance can be seen on the NE side. The enclosure wall has been used as a stone dump and is surmounted in places by a modern stone wall. There are traces of a rectangular building in the SE corner.

Source: Cadw scheduling description. F.Foster/RCAHMW 26.07.2007

The enclosure is surrounded by extensive traces of terraced fields recorded during RCAHMW aerial reconnaissance (NPRN 418946)

T. Driver, RCAHMW, 2013.