Cuillin that there are no natural sources of water on the ridge (except for winter snows and melt water), although there are a few high burns just off the main ridge from which water can be obtained. Some believe the ultimate mountaineering experience of the UK is the full traverse of the Cuillin Ridge, especially under winter conditions. The Isle of Skye's position in the warm Gulf Stream makes genuine winter conditions rare, and the very short winter days probably make a 24-hour traverse impractical. The first recorded, over two days, was in 1965 by D Crabbe, B Robertson, T Patey
Rùm Torridonian sandstone and shales resting on Lewisian gneiss. Two of the Cuillin are classified as Corbetts: Askival and Ainshval, (Old Norse for "mountain of the ash trees" and "hill of the strongholds" respectively) and Rùm is the smallest Scottish island to have a summit above . Other hills include Hallival, Trollaval ('mountain of the trolls'), Barkeval, and Sgurr nan Gillean (Gaelic: "peak of the young men") in the Cuillin and Ard Nev, Orval, Sròn an t-Saighdeir and Bloodstone Hill in the west. It is likely that only the higher peaks remained above the Pleistocene ice sheets as nunataks. Hallival and