Escuaín Canyon Nature · Puértolas, Sobrarbe, Huesca The gorges of Escuaín, in the municipal area of Puértolas, lie in the Aragonese Pyrenees, south-east of the limestone massif of Monte Perdido, within the Ordesa y Monte Perdido national park. They are formed by the Yaga river, which rises at the Cuello Viceto pass and in the Gurrundué glacial cirque, over a course of about four kilometres. The karstic morphology of the terrain has produced a network of underground cavities in the shape of a Y; three potholes, B-15, B-7 and B-1 (Fuentes de Escuaín), converge in the cavity known as La Turbina, within a system with 1,151 metres of vertical drop and more than seven kilometres of passages. Photo: Gerard from Tarbes, France (CC BY-SA 2.0) What to see and do in Puértolas