Usedom (ōˈzədôm) [key] or Uznam ōzˈnäm, island, 164 sq mi (425 sq km), in the Baltic Sea. It is divided between Mecklenburg–West Pomerania state, Germany, and Poland. Usedom is separated from the mainland by Stettin Lagoon and from the neighboring island of Wolin by the Świna Channel. The chief towns are Świnioujście (Swinemünde) in the Polish section and Usedom in the German section. Peenemünde, in the German section, was the site of a German missile research and testing station in World War II. It is generally lowland, with forests and several lakes. Grain and potatoes are the principal agricultural products; the main sources of income are tourism and fishing.