The Atlit detainee camp was a concentration camp established by the authorities of Mandatory Palestine in the late 1930s on what is now the Israeli coastal plain, south of Haifa. Under British rule, it was primarily used to hold Jews and Arabs who were in administrative detention; it largely held Jewish immigrants who did not possess official entry permits. Tens of thousands of Jewish refugees were interned at the camp, which was surrounded by barbed wire and watchtowers. The camp at Atlit now has a museum that covers the history of aliyah by non-permitted Jews. It was declared a National Heritage Site by Israel in 1987. History The camp at Atlit, established by the British government in the 1930s, was surrounded by barbed wire and watchtowers. Many of the detainees during the 1930s and 1940s were Jewish refugees from German-occupied Europe. In the late 1940s, most of the inmates were Holocaust survivors. The British authorities, acceding to Arab demands to limit Jewish immigration, refused to allow them to enter the country. At Atlit camp, the men were sent to one side, women to the other. They were sprayed with DDT, then told to undress and enter the showers. In 1939–1948, tens of thousands of Jewish immigrants were interned here, men and women separated by barbed wire. Some internees stayed as long as 23 months. WWII (camp active 1939-42) Some of the Palestine Germans, including Templers living in their own colonies, who openly supported the Nazis, were declared enemy nationals by the British authorities and were detained at Atlit prior to deportation. In November 1940, the British authorities decided to send 5000 immigrants to detention camps on Mauritius. One of these deporting ships was the Patria. To stop the deportation, the Haganah, the Jewish underground militia in Palestine, exploded a bomb in the ship's hold on November 25. The size of the explosive charge had been seriously miscalculated, and the ship sank quickly. On board were 1800 refugees; 216 drowned in the disaster. The survivors from the Patria were detained in Atlit and not deported to Mauritius. They were released after a few months. The Darien II arrived with 800 refugees in March 1941. They were detained at the Atlit camp until September 1942, when the camp was shut down. Post-WWII British camp (1945-1948) The Atlit camp was reopened in 1945 following World War II, as more and more immigrants arrived