The Valsaín Mountains located in the Sierra de Guadarrama National Park, occupy an area of 10,672 hectares and are currently an example of management and sustainability in the use of natural resources, making the obtaining of top quality wood compatible with the conservation of animal and plant species. There are up to a total of 800 tree species cataloged, without forgetting the extraordinary variety of aromatic plants and the unique mycological richness. Among the mammals, the presence of otters, roe deer, wild boars and bats stands out. The existence of more than one hundred species of nesting birds led to its declaration in 1987 as a Special Protection Area for Birds (SPA) and its inclusion in the Natura 2000 Network of protected areas.