The castle is a three-storey structure, built from rubble and slate.[1]
The east section, which was the bishop's residence, has crow-stepped gables. On the north are a projecting garderobe, with sanitary flues. On the east gable, at the level of the floors, there is a double row of corbels, and corbels which appear to have been for the purpose of supporting a roofed gallery. On the northern skewpots are small carved shields. One has the initial M, and a crown above; the other I.M., thought to stand for ‘Jesu Maria’[3] There is a circular stair tower in front.[2]
It is a category A listed building.[1]
There is ruined rectangular lean-to dovecot with rubble walls supported by later buttressing in the castle grounds.[2]