Luckily, the Biebrza marshes, located in the centre of Europe, have not been meliorated. Thanks to it, a unique natural park, the largest one in Europe, was established in Poland. It has had the status of a national park since 1973. Its area (including the buffer zone) covers 126,000 hectares. Marsh and peat plant associations, as well as forest communities with very rare plant species accompany relict plants, remnants of the glacial period. This area is also a refuge to waterbirds, both native and migrating ones. The Biebrzański National Park is of interest to researchers representing many fields, including foreign scientists.