Pirin National Park was established on 18 November 1962 in order to preserve the natural ecosystems and landscapes along with their plant and animal communities and habitats. Originally named Vihren National Park, the protected area initially covered 67.36 km2. Its territory was expanded several times until it reached its current area of 403.56 km2 in 1999. In 1983, Pirin National Park was added to the list of UNESCO World Heritage Sites as an area of outstanding natural importance. By the Constitution of Bulgaria, the park is exclusively state-owned.