Walking in the United Kingdom the scrambling suddenly becomes much more serious. In Britain, the term "mountaineering" tends to be reserved for technical climbing on mountains, or for serious domestic hillwalking, especially in winter, with additional equipment such as ice axe and crampons, or for routes requiring rock-climbing skills and a rope, such as the traverse of the Cuillin ridge, on the Scottish island of Skye. The British Mountaineering Council provides more information on this topic. Navigation and map-reading are essential hillwalking skills on high ground and mountains, due to the variability of British and Irish weather and the risk of rain, low cloud, fog
Cuillin Celtic mythology, with the hills being the place where Cuchullin learnt archery from the female warrior Scáthach. It is also suggested that the derivation of the name may reflect the "worthless" (in an agricultural or economic sense) nature of the hills, given their lack of vegetation. The Cuillin are a diverse and complex geological landscape, and there is a clear distinction visible between the two mountain types. The mountains formed from the remains of the magma chambers which fed volcanic eruptions. In the Black Cuillin the rocks cooled to form gabbro, the coarse-grained rock that makes up much of the