Skye that requires technical climbing skills to reach the summit. These hills make demands of the hill walker that exceed any others found in Scotland and a full traverse of the Cuillin ridge may take 15–20 hours. The Red Hills (Gaelic: ) to the south are also known as the Red Cuillin. They are mainly composed of granite that has weathered into more rounded hills with many long scree slopes on their flanks. The highest point of these hills is Glamaig, one of only two Corbetts on Skye. The northern peninsula of Trotternish is underlain by basalt, which provides relatively rich
Geology of Skye Part of the magma chambers for the volcanoes are exposed at the surface as major intrusions of gabbro and granite. These coarse-grained igneous rocks are relatively resistant to erosion and now form the Cuillin hills. The Black Cuillin are formed of gabbro, which erodes to form the characteristically jagged outlines, although this is in large part due to the many minor intrusions, such as dykes and cone sheets that cut the gabbro. The Red Hills are formed of granite and have a more rounded topography. All pre-Quaternary rock types on the island are affected by a major swarm of dykes,