It as a primeval forest in Aukštaitija region in northeastern Lithuania with the total area of 915 km2 (353 sq mi) of which 738 km2 (285 sq mi) is covered by trees.

Soils are sandy, light, densely covered by cup lichen.

The forest is rich in edible mushrooms, bilberries, cranberries, and cowberries.

Collection of these mushrooms and berries are an important part of the local economy.

The fauna includes many endangered species, such as the gray wolf, wood grouse, black grouse, hoopoe, Eurasian eagle-owl, osprey, mountain hare, stoat, Coronella austriaca, great capricorn beetle, and Lucanus cervus.