The Stara Planina Mountain(a part of the Balkan Mountains) is proclaimed as a nature park, and represents a mountain with high biological diversity, rich in endemic species of flora, with over 50 species on the list of endangered flora in Europe. There are over 150 springs, a lot of high-mountain streams and waterfalls.

The Suva Planina Mountain is listed as a special nature reserve, rich in flora and fauna, which become endangered due to the habitat destruction. The mountain is affected by wide variety of ecological factors and is characterized by high elevation gradient which further lead to high species and habitat diversity.