Sutjeska National Park is Bosnia and Herzegovina's largest and oldest national park, having been established in 1962. Certainly the most precious gem of National Park Sutjeska is the Strict Nature Reserve Perućica. The Perućica forest reserve was established in 1952, as "Natural reserve for scientific and educational purposes". It is one of the rarely preserved rainforests of Europe and one of the last two remaining primeval forests on the Old Continent.
Perućica Forest Reserve is 6km (3.7mi) long and 1–3km (0.62–1.86mi) wide and has an area of about 1,400 hectares (3,500 acres). It is a UNESCO recognized site. The forest has many trees that are over 300 years old and the primeval forest's vintage is stated to be 20,000 years. In some stretches, the forest is almost impregnable.
Skakavac waterfall, formed on the Perućica - a mountain creek - is located deep within the primeval forest. It is one of the highest waterfalls in the country at about 75 meters (246 ft) and it is hidden deep within the Perućica primeval forest and its massive blanket of green trees of beech and spruce that engulf entire valley.