Tantallon Castle is located in the Firth of Forth. It was built in 1375 and served as the Douglas stronghold for many centuries. It is erected on a headland with sheer 100 foot cliffs on three sides and a moat guarding the landward side. Cromwell's men under General George Monk reduced it to ruins in a twelve day bombardment in 1651. Extensive earthworks survive from the original defenses.