The remains of Y Werthyr hillfort crown a low knoll above the marshes around Afon Caradog. The site is almost isolated by marsh, except on the south. The fragmentary remains consist of two concentric lines of ramparts enclosing an area 200 yards by 220 yards, except on the north-eastern side were there are three concentric ramparts. On the west the line of the outer rampart is represented by a terrace with a retaining wall, which incurves towards the road which now cuts through the fort from north-west to south-east.

RCAHMW, January 1993.