Three fast, windy and electric downhill sections. The trilogy of amazing descents made up of Sos-Castejón, Arasán Express and Gabás-El Run are a reason worth enough to come to Puro Pirineo from far away. The route consists in three different loops departing from Castejón de Sos and connecting the mentioned descends by paved roads and dirt tracks, some of them rather steep. An interesting loop extension from Sos takes route 20 (red) to climb up to Ramastué and adds another technical enduro singletrack to the route. It’s marked with a black line on the map.