The biodiversity, ecosystems and the pristine landscapes are protected by Rila National Park declared in 1992, which is Bulgaria's largest spanning a territory of 810.46 km2, and Rila Monastery Nature Park covering another 252.535 km2. There are four nature reserves in the former — Parangalitsa, Central Rila Reserve, Ibar and Skakavitsa, and another one, Rila Monastery Forest, in the latter. Parangalitsa was declared a UNESCO Biosphere Reserve in 1977, while the Central Rila Reserve is the largest one in the Balkans with an area of 123.937 km2.