The Germans built four concentration camps on the island, subcamps of the Neuengamme concentration camp (in Hamburg, Germany). Each subcamp was named after one of the Frisian Islands: Lager Norderney at Saye, "Lager Borkum" at Platte Saline, Lager Sylt near the old telegraph tower at La Foulère and Lager Helgoland, in the northwest corner of the island. Over 700 people died in the Alderney concentration camps (out of a total inmate population of about 6,000). These were the only Nazi concentration camps on British soil.