The highest mountain in Britain, at 1,345 metres above the head of Loch Linnhe, is a slab of granite, gabbro, and Devonian sediments tilted improbably to the sea. The summit plateau is broad, often clagged in cloud, and the famous Tower Ridge and Carn Mor Dearg arête give it one of the longest and most exposed mountain edges in the country. On a clear day — perhaps fifty days a year — the view stretches from the Cuillin of Skye to the Cairngorms.
The standard tourist route (the "Mountain Track" or Pony Track) leaves from the visitor centre at Glen Nevis and takes six to eight hours for the round trip. It is well-graded but long and exposed above the half-way lochan, with serious cliffs immediately right of the summit zigzags. Conditions can be wintry in any month. The more technical CMD arête and the climbs on the north face — Britain's largest cliff — are the preserve of more experienced walkers and climbers.