Smoo Cave in the far northern Highlands is arguably one of – if not the – most impressive natural wonders in Scotland. This is a cave that’s absolutely monumental in size, and the cave entrance has the privilege of being the largest sea cave entrance in Britain – something you’ll only really appreciate once you visit the place. To get to Smoo Cave head towards the village of Durness in Sutherland (the most northwesterly village on the Scottish mainland) and stop at the car park on the village outskirts.