Foz de Lumbier Nature · Lumbier, Sangüesa, Navarra A canyon just over a kilometer long carved by the Irati river into the limestone rock next to the Sierra de Leyre, with nearly vertical walls between 150 and 400 meters high. Declared a Reserva Natural (Nature Reserve), it protects an important colony of birds of prey, including griffon vultures and Egyptian vultures; the trail follows the route of the old Pamplona-Sangüesa railway, known as "El Irati," now converted into a greenway. Photo: The original uploader was Jsanchezes at Spanish Wikipedia. (CC BY-SA 3.0) What to see and do in Lumbier