Spread over an area of over 27,000 ha, at an altitude between 1008 and 2914 m in the Pirin Mountains, southwest Bulgaria, the site comprises diverse limestone mountain landscapes with glacial lakes, waterfalls, caves and predominantly coniferous forests. It was added to the World Heritage List in 1983. The extension now covers an area of around 40,000 ha in the Pirin Mountains, and overlaps with the Pirin National Park, except for two areas developed for tourism (skiing). The dominant part of the extension is high mountain territory over 2000m in altitude, and covered mostly by alpine meadows, rocky screes and summits
Extending over an area of 27,400 ha and lying at an altitude of 1,008-2,914 m in the Pirin mountains, south-west Bulgaria, Pirin National Park has a limestone Balkan landscape, with lakes, waterfalls, caves and pine forests. The rugged mountains, with some 70 glacial lakes scattered throughout them, are home to hundreds of endemic and rare species, many of which are representative of the Balkan Pleistocene flora. The mountains also have diverse and unique landscapes of great aesthetic value.
Pirin Mountain stretches from north-west to south-east between the valleys of the Strouma and Mesta rivers. There are many rivers and waterfalls. Winter in the upper parts is cold and long with snow cover remaining for five to eight months. Summer is cool and short.
The presence of limestone rocks, the southerly position of the range and close proximity to the Aegean, coupled with its relative isolation, have made Pirin Mountain an important refuge for many species. Forests in the park are mainly coniferous with endemic Macedonian pine being widespread and forming the timberline in the granite part of the mountain. Endemic Bossnian pine occurs in the highest zone of the karst area. Unique stands of Pinus peuce and Pinus leucodermis , up to 250-300 years old and 30-45 m high, are found in Baiouvi Doupki-Djindjiritsa Reserve. Some individual Pinus leucodermis trees are over 500 years old. Silver fir, Austrian pine, spruce, Scots pine and beech form a mixed coniferous forest type.
Generally, the timberline has developed as a result of human interference over a long period and descends as low as 2,000 m, but in some places reaches 2,200-2,300 m. In the subalpine zone there are thickets of dwarf mountain pine and Juniperus sibirica . Above 2,400-2,600 m is a layer of alpine meadows, stony slopes, screes, rocks, etc.
The flora of Pirin, comprising as it does many rare species, is of great interest and beauty. One of the most active flora speciation in Bulgaria is situated in the limestone part of the mountain. Pirin has a mixture of central European, Alpine, Balkan mountain and sub-Mediterranean species, but in addition there are about 30 local endemic species.
There is a wide variety of animal species including many endemic species and glacial relicts among the invertebrate fauna. Threatened bird and mammal species include brown bear, grey wolf, pine marten, rock marten, polecat, badger, otter, wild cat, red deer, roe deer, wild boar, Balkan chamois, golden eagle, capercaillie, hazel grouse, eagle owl, black woodpecker and three-toed woodpecker.
In 1963 Vikhren National Park (6,212ha) was established in the northern part of the Pirin mountains under Decree No. 3074 of 6 November 1962 of the Committee of Forestry and Forestry Management. In 1976 it was enlarged 27,OOOha and renamed Pirin National Park (Decree No. 1036 of 3 March 1976, Ministry of Forestry). Pirin NP was enlarged to 40,060ha in 1987 (Decree No. 1036 of 17 November, Committee of Environmental Protection at the Council of Ministers. Baevi Doubki Natural Reserve was established in 1934, extended in 1976 and renamed Baevi Doupki - Dzindzeritza (2,873ha) in 1979. It was declared a biosphere reserve in 1977.
