The Bialowieza National Park covers the central part of Białowieża Forest. Białowieza National Park protects last natural forest at the European Lowland Area, having the primaeval character, identical with the one which covered the area of deciduous and coniferous forests years ago. A European bison – the biggest European land mammal – is the symbol of the Park. Białowieza Forest became last mainstay for the lowland European bison. At present, Białowieza Forest comprises the largest free-living population of European bison in the world. There are approximately 500 European bison living in the Polish part of Białowieza Forest. Białowieza National Park is the only Polish natural property designated by UNESCO as a World Heritage site.