It is believed that the castle, on Castle Hill, was a motte, encircled by a wide ditch and outer rampart, except on the north where a landslip has destroyed it. The ditch is about 6.0 metres (19.7 ft) wide and 1.75 metres (5 ft 9 in) deep; the outer bank is about 6.0 metres (19.7 ft) wide and 1.5 metres (4 ft 11 in) high.
- Coventry, Martin (2001). The Castles of Scotland. Musselburgh: Goblinshead. p. 138 ISBN 1-899874-26-7
- "Cullen Castle". Stravaiging around Scotland. Retrieved 2016-08-25.
- "Cullen, Castle Hill". Royal Commission on the Ancient and Historical Monuments of Scotland. Retrieved 2016-08-25.