Blackness Castle sits on a rocky promontory jutting into the Firth of Forth, about four kilometres north of Linlithgow town. Its unusual ship-like plan — the main tower positioned like a prow, the perimeter walls rising like gunwales — makes it one of the most distinctive silhouettes among Scottish castles. It served as a state prison for much of the 16th and 17th centuries, holding notable prisoners including Cardinal Beaton's opponents.
Historic Environment Scotland manages the castle, which is freely accessible. The walk from the small car park takes about ten minutes, and the views across the Firth of Forth to the hills of Fife are excellent on a clear day. The castle is remote enough that visitor numbers stay manageable, and the wind off the estuary tends to discourage lingering crowds. Drive or take a taxi from Linlithgow — the walk from town is long on minor roads.