Castle Arnold, destroyed in 1177, is traditionally believed to be the site of the palace of Kings of Over Gwent. The visible remains at the site include a natural mound, approximately 80m east to west by 50m and up to 6.0m high set on the fringes of the Usk flood plain. A subrectangular enclosure, c.50m E-W by 26m, upon the summit of the mound, is defined by low banks on the west and east, elsewhere by steep natural slopes. Attached on the western side is a second enclosure, c.32m E-W, defined by a bank on the west.
(source Os495card; SO31SW26)

J.Wiles, RCAHMW, 13 May 2004