Pirin National Park is located in the Pirin Mountains, situated in the southwestern part of Bulgaria. The territory of the National Park covers seven municipalities from the Blagoevgrad district – Bansko, Gotse Delchev, Razlog, Sandanski, Strumyani, Kresna and Simitli. Pirin National Park was established in 1962 and was originally called Vihren National Park. At that time, its area was 6212 ha and covered the highest parts of the Demyanitsa and Vihren areas. Over the years, the territory of the park has expanded several times, and today Pirin National Park covers over 40,000 ha. Since 1983, the National Park has been under the protection of UNESCO. One of the oldest reserves in Bulgaria, Bayuvi Dupki-Dzhindzhiritsa, is also part of Pirin National Park. It was declared a protected area in 1934 to preserve the natural relict forests of white and black mulberry and the great variety of plant and animal species. In 1977, it was declared a biosphere reserve under the UNESCO's Man and the Biosphere Programme. In 1994, the other reserve in the park, Yulen, was declared the same.