An area that changed flags several times in the 20th century, Eastern Poland consists of Podlaskie, Lublin and Subcarpathian Voivodships (Provinces). The largest cities in each are Bialystok, Lublin and Zamosc respectively. The Masurian Lake District in the northeast includes Wigry National Park and Lake Hancza, the deepest lake in Poland. Bialowieza National Park, on the Belarusian border, protects one of the last remaining sections of a huge primeval forest that once covered Eastern Europe.