The continuous line of the inner German border ended at the peninsula of Priwall, still belonging to Travemünde, but already on the east side of the Trave. From there to Boltenhagen, along some 15 kilometres (9.3 mi) of the eastern shore of the Bay of Mecklenburg, the GDR shoreline was part of the restricted-access "protective strip" or Schutzgebiet. Security controls were imposed on the rest of the coast from Boltenhagen to Altwarp on the Polish border, including the whole of the islands of Poel, Rügen, Hiddensee, and Usedom as well as the peninsulas of Darß and Wustrow.[1]