Old Radnor Castle is an oval moated enclosure, measuring c.40m by 33m, defined by a steep sided ditch, 2.6m maximum depth, and close by Old Radnor church (NPRN 306985). It is set beneath steep slopes to the east, whilst the ground falls away to the west and north. The site is alluded to in a terrier of 1607 as a 'moated parsonage'.

T. Driver, RCAHMW, 31.1.2011, Additional information from R. Silvester.