Majdanek or KL Lublin was a Nazi German concentration and extermination camp established on the outskirts of the city of Lublin during the German occupation of Poland in World War II. Although initially purposed for forced labor rather than extermination, the camp was used to kill people on an industrial scale during Operation Reinhard, the German plan to murder all Jews within their own General Government territory of Poland. The camp, which operated from October 1, 1941 until July 22, 1944, was captured nearly intact, because the rapid advance of the Soviet Red Army during Operation Bagration prevented the SS from destroying most of its infrastructure, but also due to ineptitude of commandant Anton Thernes who failed in his task of removing incriminating evidence of war crimes. Therefore, Majdanek became the first concentration camp discovered by Allied forces. Also known to the SS as Konzentrationslager Lublin, Majdanek remains the best preserved Nazi concentration camp of the Holocaust.