Cuillin Harta Corrie and Coire Na Creich in the Cuillin: Boswell and Johnson visited Skye during their tour of the Western Isles in 1773, and observed snow falling on the summits of the range in September. Boswell described the Cuillin as "a prodigious range of mountains, capped with rocks like pinnacles in a strange variety of shapes". Uniquely for a group of Scottish mountains there are no records of the majority of the Cuillin summits having been climbed prior to the start of mountaineering as a leisure activity in the Victorian era, a situation reflected in the fact that around half
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,