This 50 ft (15 m) high sea cave is the largest coastal cave in the UK and really has to be seen to be believed. Smoo Cave is set into limestone cliffs at the eastern end of the village of Durness and can be reached by a purpose-built pathway. See the impressive waterfall inside, which falls some 80 ft into the cave.

From April to September you can also take a tour further underground by boat. Nearby you can also walk the beautiful sands of Sango Bay and Balnakiel beach or climb Ben Hope, Scotland’s most northerly Munro.