Kildrummy Castle in Aberdeenshire

You're standing at Kildrummy Castle, or rather, at what's left of it. Even as a ruin, it's one of the largest thirteenth-century castles still around in eastern Scotland. For centuries this was the seat of the Earls of Mar. Start by looking at the shape. The plan is like a shield. The flat back sits above a steep ravine, while on the opposite side the walls come to a point. That's where a massive gatehouse with twin towers and a drawbridge once stood.