Uckermark is a Kreis (district) in the northeastern part of Brandenburg, Germany. Neighboring districts are (clockwise from the south) Barnim and Oberhavel, the districts Mecklenburgische Seenplatte and Vorpommern-Greifswald in Mecklenburg-Vorpommern, and to the east Poland (Police County and Gryfino County). It is the largest district of Germany areawise. The district is named after the historical region of Uckermark.The Uckermark is named after the Uecker river, which is a tributary of the Oder. The Oder River, forming the Polish border, bounds the district in the east. The district is characterised by 600 lakes and 2,800 km of rivers. Rare animals still live in the lakeland, such as ospreys, beavers and otters.The western parts of the Lower Oder Valley National Park are located in the district.