Burn o’ Vat is a huge glacial pothole — a rounded cauldron of rock scoured out by meltwater at the end of the last ice age — hidden in the Muir of Dinnet reserve near Dinnet. A short walk up a narrow gorge leads you into the cavern, where the burn tumbles through a gap in the rock. There’s a car park at the start. Free and open, and good fun with kids, though you may well get your feet wet at the entrance.

© Alan Findlay / Geograph · CC BY-SA 2.0