Foz de Arbayún Gorge

Foz de Arbayún is the deepest and most dramatic river gorge in Navarre, carved by the Río Salazar through the limestone massif between the Sierra de Leyre and the Sierra de Illón in the Valle de Salazar. The gorge stretches approximately 6 kilometres through sheer vertical limestone walls rising up to 600 metres above the riverbed, which remains in permanent shadow during winter months. The standard viewpoint is reached from a parking area on the NA-178 road near Navascués, where a stone-railed mirador overhangs the cliff edge above the canyon floor. The gorge is best known among ornithologists and birdwatchers as one of the most significant griffon vulture breeding sites in Navarre, with a colony of several hundred nesting pairs. Visitors with binoculars frequently observe multiple birds soaring simultaneously on thermals within the canyon. Egyptian vultures, golden eagles, peregrine falcons, and alpine swifts are also regularly recorded. A trail inside the gorge follows the river through the deepest section, but the route involves river crossings and is only practical during dry summer months when water levels drop. The canyon is accessible by road year-round and the mirador viewpoint requires no hiking. The gorge is protected under the Reserva Natural Foz de Arbayún designation.