Alto de L'Angliru Activity · Riosa, Oviedo, Asturias Twelve and a half kilometres of climbing from La Vega with 1,266 metres of ascent, an average of 10% and ramps that touch 24% at Cueña les Cabres. It made its debut in the 1999 Vuelta a España and has remained the most feared climb in Spanish cycling. Photo: Wikipedia / Wikimedia Commons (CC BY-SA) What to see and do in Riosa