[1] It became part of the Ordesa y Monte Perdido National Park in 1918, making it one of Spain's earliest protected natural areas.

Notable tree species include Scots pine (Pinus sylvestris), Silver fir (Abies alba), and European beech (Fagus sylvatica).

[6] Other wildlife includes griffon vultures (Gyps fulvus), golden eagles (Aquila chrysaetos),[7] and brown bears (Ursus arctos),[8] though the latter are extremely rare.

Designated a UNESCO Biosphere Reserve in 1997, the park implements measures to balance tourism with habitat protection, including restricted access zones.

[9][10] The valley's formation stems from the collision of the Iberian and Eurasian tectonic plates during the Alpine orogeny, creating folds and faults in its limestone and dolomite bedrock.