Ben Macdui is the second-highest mountain in Scotland and all of the British Isles, after Ben Nevis, and the highest of the Cairngorm Mountains. The summit is 1,309 metres (4,295 ft) above sea level and it is classed as a Munro. Ben Macdui sits on the southwestern edge of the Cairngorm plateau, overlooking the Lairig Ghru pass to the west, and Loch Etchachan to the east. It lies on the boundary between the historic counties of Aberdeenshire and Banffshire.