The range consists of three major massifs: Central (also known as Urrieles), Eastern (Ándara) and Western (also known as the Picos de Cornión). The Central and Western massifs are separated by the 1.5 kilometres (0.93 mi) deep Cares Gorge (Garganta delCares), with the village of Caín at its head. The waters in the Cares mostly arise fromcave resurgences. Some of the water in the Cares river is diverted through ahydroelectric scheme, with a canal running in the northern wall of the gorge toCamarmeña. An access path next to the canal provides a spectacular walk.
Almost all of the rock in the Picos is limestone, and glacial action has contributed to create an impressive area of alpine karst. The highest peak is Torre de Cerredo, with an altitude of 2,650 metres at 43°11′51″N 4°51′06″W. Many other peaks reach altitudes of over 2,600 m. The area is popular with mountaineers, climbers and mountain walkers. There is a good network of well-established mountain refuges. The best-known climbing site is the Naranjo de Bulnes or Picu Urriellu, in the Urrieles massif which can be considered the most famous climb in Spain
