Mountain range of San Mamés Nature · San Martín del Rey Aurelio, Nalón, Asturias Image of San Martín del Rey Aurelio, not of the place itself. A ridge running from near Sienra to Pico Tresconceyos and forming the boundary with Laviana, extending the La Faya slope southwards. Its hillsides enclose the San Mamés valley, one of those that open to the south of the River Nalón. Photo: LMLM (CC BY-SA 3.0) What to see and do in San Martín del Rey Aurelio