Glencoe is probably Scotland's best known glen due as much, perhaps, to its dark history as for its magnificent mountain scenery. It is regarded by many as the home of Scottish mountaineering and is extremely popular with hillwalkers and climbers. The glen was formed by an ice age glacier and its long floor is less than half a mile wide. One enters Glencoe from the east below the Buachaille Etive Beag just west of Lochan na Fola, from where waters of the infant River Coe commence their run west to their outflow in Loch Leven. The river passes over several waterfalls en route and also the lovely Loch Achtriochtan.
The south side of the glen is a complex assemblage of peaks, ridges, buttresses and corries also known as 'The Three Sisters' that support Bidean nam Bian, 1,150 metres (3,770 ft), the highest summit in Argyll. There are three subsidiary summits of the Bidean nam Bian massif, namely Stob Coire Sgreamhach, Stob Coire nan Lochan and Stoob Coire nam Beithe. In contrast the north side of the glen is a stark mountain wall with a rocky and pinnacled crest, the Aonach Eagach ridge. The ridge is crossed at the eastern end by the Devil's Staircase, an old military road opposite Buachaille Etive Mor. The western end terminates with the conical Pap of Glencoe, also known as Sgurr na Ciche, above Glencoe village, at the point where the glen opens out to Loch Leven.