The Laciana Valley is one of the most special corners of the Cantabrian mountain range. Fragmented by the upper course of the Sil River and some of its tributaries, it is a succession of high mountains and deep valleys in which a large number of biotypes coexist that fully justify its declaration of UNESCO Biosphere Reserve.

In this unaltered landscape covered by a mosaic of forests of birch, rowan, maple, yew, holly,

Hazelnut, ash and beech trees, as well as blueberry and high mountain brañas with their typical shepherd's huts, two of the most emblematic animal species of the northern peninsula find their habitat. Here, the brown bear population is one of the most important in Spain, while that of the Cantabrian capercaillie is the most numerous and representative.