Stara Planina (Old Mountain) Nature Park is a mountainous region located in eastern Serbia, in the municipality of Zajecar, Knjazevac, Pirot and Dimitrovgrad. It covers an area of 142,219 hectares. It is under the state protection as a natural resource of great importance, classified in the first category. The Stara Planina is nature park from 1997, as an area of extremely value from the standpoint of the diversity of flora and fauna and their communities, as well as geological, geomorphological and hydrological characteristics. The relief of Stara Planina is a very stratified. The main characteristic of the relief of the area are sharply etched and deep valleys of short flows. This characteristic is caused by, for the most part, the geological structure of the field.