At the eastern edge of the Sierra de Gredos discovered a small, special territory: Iruelas Valley. He drained by a series of mountain streams -the main, Iruelas, is a tributary of the river Alberche- appear its slopes covered with valuable forest formed by a great diversity of species.

Among all stand out European black and Corsican pines, which even a large and ancient specimens are preserved. Within the limits of this valley the largest colony of black vultures of all Castilla and Leon (about 100 pairs) and one of the largest in the European continent is installed.

The limits of this Nature Reserve extending from the 1,950 meter summit of Cerro de la Escusa up to 730 meters on the banks of Burguillo Lake. Most of it is located in the municipality of El Barraco. Next to this reservoir can be seen an old town in which they lived resineros working in the bush.

The valley also has been declared a Special Protection Area for Birds (SPAB).