and is rich in hot springs in the fault areas at the foothills, including the hottest spring in South-eastern Europe in Sapareva Banya.

The mountain range has varied flora and fauna with a number of endemic and relict species and some of the best preserved forests in the country. The biodiversity and the pristine landscapes are protected by Rila National Park which covers much of the mountain; the rest lies within Rila Monastery Nature Park.