With a lenght of 20 km, from the brigde of the Navarros to the Collado of the Mulos, it is Peripheral Protection Area of the Ordesa and Monte Perdido National Park , Special Protection Area for Birds (ZEPA), Place of Community Interest ( LIC) and is integrated into the “Ordesa-Vignemale” Biosphere Reserve.
3 km from Torla, you can find the Puente de los Navarros , the initial access to Bujaruelo Valley. Start theestrecho de Bujaruelo , on a track that continues for 3 km. Shortly before reaching the puente Nuevo , you can see the Carpín cascade (120m descent), to the left of the track.
A pretty path starts from here on the right before crossing the bridge, which leads to the chapel of Santa Elena, hidden among the vegetation. 4 km later you can contemplate the ruined Romanesque chapel of St. Nicholas ,in a beautiful setting.
From St. Nicholas (1338m) multiple trips can be made ( Puerto de Bujaruelo , Ara Valley and The Otal Valley ).