Tantallon features extensive earthworks and a very imposing red stone curtain wall that protects one side of a promontory that is otherwise surrounded by steep cliffs and the sea. The scenic location on the Firth of Forth, overlooking Bass Rock, would be impressive enough, but the sheer scale of the curtain wall, 15m (50ft) high and 3.5m (12ft) thick, make this castle stand out. You can climb to the top of this wall to enjoy the great views.