Aneto and Posets are the Pyrenean giants. Their massifs hang over the high-lying valleys of Chistau, Benasque and Barrabés, offering some of the most grandiose scenery in the mountain range included within the boundaries of this Nature Park. 

A mineral kingdom of granite, slate, schist and limestone, with beautiful u-shaped valleys, such as Estós, Eriste and Vallibierna, on whose mountain tops the last of the cirque glaciers are just about holding out. Almost one hundred mountain lakes, numerous torrents and rivers further enhance the charm of these spots.

The dense network of paths and mountain shelters facilitate mountaineering, from short but rewarding walks to long hikes and climbs.