Chwaniów Nature Reserve was established in 1996 and located in Ustrzyki Dolne community on the north-eastern slopes of the range of the same name. This range is also the northernmost fragment of Polish part of the Eastern Carpathians. It covers an area of 354.47 ha. The purpose of creating Natural Reserve was to preserve magnificently cultivated and preserved Carpathian subalpine beechwood forest in a damp component with a perennial honesty. It covers nearly 80% of the total area. So vast surface of this community does not occur anywhere else in the Eastern Carpathians. In the groundcover is a number of rare and protected species of plants. These are, among others: eastern pictures, broad-leaf orchid, mezereon, New England hawkweed and polystichum. Remarkably precious tree stands of hundred and more years old are in the Reserve. Vast complexes of old trees favor the settlement of numerous "forest" species e.g. horned owl, black stork and Carpathian deer.