Thanks to its geographical location, Sallent de Gállego has a great diversity of landscapes. Some of them, thanks to their quality or uniqueness, have protection figures.

The most important of these protection figures would be the Ordesa-Viñamala Biosphere Reserve, which was declared as such in 1977 by UNESCO and, together with the Sierra de Grazalema, was the first biosphere reserve declared in Spain. This established the framework for achieving the objective of harmonising the conservation of biological and cultural diversity and economic and social development through the relationship between people and nature.

At the beginning, the Reserve had an area of 51,396 hectares and occupied the territories of the former Viñamala National Hunting Reserve and the surface area of the Ordesa National Park prior to its extension in 1982.

In May 2013, the reserve was extended to cover 117,364 hectares, at which point Sallent became part of the reserve along with other municipalities in the Alto Gállego region, such as Biescas, Hoz de Jaca, Panticosa and Yésero, as well as Bielsa, Broto, Fanlo, Puértolas-Escalona, Tella-Sin and Torla, in the Sobrarbe region.

It is one of the best representations of the mountain ecosystems of the Pyrenees. The landscapes typical of the high mountains stand out, with glaciers and the formations such as valleys or moraines that they create, deciduous forests, pine and fir forests and high mountain pastures, extensive plant formations of singular value.

It is also home to species of flora of singular value, such as the edelweiss or the lady's slipper, as well as species of fauna with some degree of threat, such as the bearded vulture, the chamois, the Pyrenean desman, the ptarmigan, the capercaillie or the black woodpecker, whose conservation is fundamental for the maintenance of biological diversity.

The Biosphere Reserve receives more than a million visitors every year thanks to its enormous tourist attractions, as well as the wide range of services and leisure activities that can be found in the municipalities that make it up.