Lochleven Castle

You'll need a boat to reach this one, which is rather the point. Lochleven Castle sits on an island in the middle of Loch Leven, near Kinross, and getting there involves a short ferry ride that properly sets the mood for what's essentially a 14th-century fortress ruin surrounded by water on all sides. The castle itself is substantial enough - you can still make out the main tower and courtyard walls - but the real draw is the isolation. Being stranded on an island, even temporarily, does something to how you experience a place.

Historically minded visitors will appreciate the serious credentials: Mary, Queen of Scots was imprisoned here in 1567, which gives the grey stones a certain weight. The tower is climbable if you're steady on your feet, and the views across the loch towards the Ochil Hills justify the climb. It's not a huge site - you'll cover the ground in about an hour unless you're the type who reads every interpretive panel.

Families with younger children might find it underwhelming once the novelty of the boat ride wears off. Teenagers or keen history types will get more from it. The site is managed by Historic Environment Scotland, so it's free to visit the island itself, though the ferry crossing costs a few quid.

If you're based at Gallowhill Caravan & Camping Park or the excellent Wild Goose Glamping, this makes a straightforward morning outing. Kinross is close enough that you could combine it with lunch and a walk round the loch itself.