Motte and bailey complex. The motte incorprates a natural sandstone outcrop standing 11m above the floodplain. It is 60m wide at the base and the flat top is 10m in diameter. Three irregularly shaped baileys are separated from the motte by a ditch. Cainhoe was the centre of the Barony of Cainhoe, held by the d'Aubigny family from the Conquest until the mid 13th century. No castle is mentioned in 1272 when the male line had been extinguished and the estate divided. By 1374, the fortifications were ruinous. The earthwork remains of the castle and surrounding features were mapped from aerial photographs.
(See TL03NE24 for associated deserted village and TL03NE25 for succeeding moated manorial works).