Located in Oranienburg, just 35 km north of Berlin, this was the primary facility in the camp system; the administrative center; and the training facility for SS officers who would be posted to other camps. It was opened in 1936 and remained open until liberation in 1945. Prisoners included the usual Nazi "enemies" -- criminals, communists, homosexuals, Jehovah's Witnesses, and jews; who were forced to labor in nearby arms workshops. Some 30,000 of them died from exhaustion, disease, malnutrition, medical experiments, or harsh treatment by the guards. Executions took place, especially Soviet Prisoners of War, first by shooting or hanging, and then in 1943 by a gas chamber that let the SS murder prisoners en masse. Near the end, about 10,000 Red Army Prisoners of War were executed in the Genickschussanlage ("neck shooting facility") known as "Station Z," similar to the system used for the Buchenwald Murders. As the Red Army approached in April 1945, the SS ordered 33,000 inmates on a death march. Thousands did not survive. Finally, on 22 April 1945, the remaining 3,000 inmates, including 1,400 women, were liberated by the Red and Polish Armies.  Link. Map