Torres Peak Nature · Caso, Nalón, Asturias At 2,104 metres it is the highest point of the council of Caso, on the boundary with Aller, within the Sierra de Valverde and Redes Natural Park. Its south face, darkened by its quartzite nature, offers some of the most interesting climbing routes in the Cantabrian mountain range; the normal ascent route starts from the San Isidro pass. The sharp, pointed shape of its summit makes it easily recognisable from other mountains in Asturias, León and even from the Montaña Palentina, and it overlooks the valleys of the Aller and the Nalón. Photo: Teofrasto820 (CC BY-SA 4.0) What to see and do in Caso