Location: La Palma (Canary Islands, Spain). Area: 189 hectares. Altitude: 2396 m. Geographical coordinates of the GTC: Longitude: 17º 53 ´ 33" West. Latitude: 28º 45´ 25" North. At Roque de los Muchachos Observatory (ORM), on the rim of the Parque Nacional de la Caldera de Taburiente, at a height of 2396 m, in the municipality of Garafía, is to be found one of the most extensive arrays of telescopes in the world. The Observatory is ideal for both nocturnal observations and solar physics. It also hosts high energy astrophysics experiments.