A wild mountain region in the Pyrenees, with peaks rising to 3,017 m (Besiberri Sud) and with nearly 200 lakes, many of them of glacial origin, the park comprises:
the core area (13,899.96 hectares)
a peripheral or buffer zone surrounding the park (26,079.24 hectares)
The park has an elevation range from 1,600 to 3,000 metres and contains four major vegetation zones: lower montane, upper montane, subalpine and alpine. It has a great variety of alpine vegetation, including dark-coniferous mountain forest (fir, mountain pine) and subalpine pine forest.
