Lager Sylt was a Nazi concentration camp on Alderney in the British Crown Dependency of the Channel Islands, in operation between March 1943 and June 1944. The Germans built one concentration camp and three labour camps on the island, subcamps of the Neuengamme concentration camp (located in Hamburg, Germany). Each subcamp was named after one of the Frisian Islands: Lager Norderney located at Saye, Lager Helgoland at Platte Saline, Lager Sylt near the old telegraph tower at La Foulère and Lager Borkum, situated near the Impot. 700 people are estimated to died in the camps on Alderney, although it is now believed to have been higher. This was the only Nazi concentration camp on British soil.