Cuillin in colour, particularly in the shade, but when in sunlight the Black Cuillin can appear grey to brown in colour. The main ridge forms a narrow crest, with steep cliffs and scree slopes. The ridge is about 14 km long (measured from Gars-behinn in the south to Sgùrr nan Gillean in the northeast), and curves in an irregular semi-circle around Loch Coruisk, which lies at the heart of the range. The highest point of the Cuillin, and of the Isle of Skye, is Sgùrr Alasdair in the Black Cuillin at 992 m (3,255 ft). The Red Cuillin are mainly composed
Cuillin and magnetic abnormalities that make compass reading unreliable. The majority of scramblers heading on to the Black Cuillin do so via routes from Glenbrittle (where there is a campsite and a youth hostel) or Sligachan for the northern peaks: due to the remoteness of Loch Coruisk, which can only be reached by boat or a "c." 10 km walk from Elgol, routes starting from this side are less frequented. In addition to climbing individual peaks, there is the challenge of a full traverse of the main Black Cuillin ridge. Although only in length, the average traverse is likely to take