The area in which ADECOAR works has a total area of 1,590.72 km2. The mountains of Alto Arlanza, called the Sabinares del Arlanza, and the valleys formed by its rivers make up a total ZEPA (Special Protection Area for Birds) area of 6,322.37 hectares and an LIC (Site of Community Importance) area of 6,534.18 hectares.