It is the second oldest park in Spain and the first one in Aragón, after being declared on august 16th of 1918. Now, the park has different protection figures other than the National Park, in 1977 it was declared Biosphere Reserve, in 1988 Zone of Special Protection for Birds and in 1997 it became a World Heritage Site by UNESCO. It is also a Place of Community Importance.
The orography of the Park is dominated by the Tres Sorores massif, Treserols, the highest calcareous massif in Europe. Its highest elevation is Monte Perdido, which radially descends a series of impressive mountain ridges and glacial valleys.
The vegetation of the Park consists of 1400 species, representing almost 45% of the plants of the Aragonese Pyrenees, of which 83 are exclusive to the Pyrenees, that is, half of the endemism of the mountain range. In the 30 peaks or more, of more than 3000 of the protected territory and its periphery you can see about 100 species, which accounts for two thirds of the alpine vegetation of the Pyrenees.