Pen y Clawdd Castle is a ditched mound with a double moat, roughly circular in shape, with a diameter of approximately 28m to 30m and about 2.4m high.
[1] The castle is in Llanvihangel Crucorney, about five miles to the north of Abergavenny, Monmouthshire, in south east Wales and lies between the Usk and Monnow rivers.
[1] Very little is known of the exact origins of the castle, but it may have been built by Roger de Hastings during the 11th century, as one of a number of forts created after the Revolt of the Earls in 1075.
[10] The surveys and excavations suggested that there was a large rectangular masonry structure on the mound which suffered fire damage and partly collapsed.
[11] Phillips suggests that the site is a fortified house from a later period,[12] but may have been preceded by a motte and bailey.