Since 1918, the Valley of Ordesa has been a 2 066ha national park. Since 1982, the park has encompassed the whole Massif of Monte Perdido and the valleys of Ordesa, Añisclo, Escuain and La Pineta, in all 15 608ha. The limestone reliefs are striking: at the bottom of the Ordesa Valley flows the Arazas (trout fishing), hidden beneath lush vegetation. The vegetation in the Añisclo Canyon, consisting of dwarf pine trees clinging to the limestone walls, makes it an attractive place.