Perched on a rocky spur overlooking the Firth of Forth, the castle was one of the four strongholds in Scotland to house a garrison A royal castle, prison for Covenanters and artillery depot, the fortress was then turned into a youth hostel. The central tower dates from the 15C, the curtain walls and south tower from the 16C. There is a splendid view over the Firth of Forth and the bridges on the starboard side.