Impressive ruins of the fortress of the Red Douglases, built in the 14th century. Besieged by James IV and V, it ultimately fell to Oliver Cromwell's forces under General Monck in 1651, and was destroyed. It is an unusual castle; situated on a headland, it has a single curtain wall blocking off the entire site, with defence on the remaining three sides relying on the sheer cliffs and the surrounding sea. Tantallon offers great views of the Bass Rock - and a grim pit prison. Ugh!