Dornoch Castle, in the north of Scotland. The relatively modest fortress was built sometime in the late 1400's as a residence for the bishop of the nearby 13th century cathedral. By 1922, it was privately owned, modernized and opened as a hotel in 1947. I'd stay in the Old Courtroom, one of two deluxe rooms in the oldest part of the castle, with 16-foot ceilings, stone walls, big fireplace, and hand-carved four-poster bed. Comes with full Scottish breakfast.