The Cuillin is a range of mostly jagged rocky mountains on the Isle of Skye. The main Cuillin ridge is also called the Black Cuillin to distinguish it from the Red Cuillin, which lie to the east of Glen Sligachan. A full mountain traverse of the main Black Cuillin ridge is 11 km (7 mi) in length. The first recorded traverse in under 24 hours was on 10 June 1911 by Leslie Shadbolt and Alastair C. McLaren, in 12 hours 18 minutes top to top. Some believe the ultimate mountaineering experience of the UK is the full traverse of the Cuillin Ridge, especially under winter conditions. The first recorded, over two days, was in 1965 by D. Crabbe, B. Robertson, T. Patey and H. MacInnes.