Carn Eighe is a mountain in the Northwest Highlands of Scotland. Rising to 1,183 metres (3,881 ft) above sea level, it is the highest mountain in Scotland north of the Great Glen, the twelfth-highest in the British Isles, and, in terms of relative height, it is the second-tallest mountain in the British Isles after Ben Nevis. Carn Eighe lies between Glen Affric and Loch Mullardoch, and is at the heart of a massif along with its twin peak, the 1,181-metre (3,875 ft) Mam Sodhail.