Natzweiler-Strutthof is a concentration and labor camp located approximately 30 miles south of Strasbourg in France. It operated from May 1941 through September 1944. At its height in 1944, its more than 25,000 prisoners in the main camps and its numerous satellites worked in the nearby granite quarries, as well as in an underground arms factory. Members of the French resistance apprehended as part of the Nacht und Nagel program were among the prisoners held here. Dozens of inmates from Auschwitz, mostly Jews, as well as Sinti and Roma, were transferred to Natzweiler and murdered in the small gas chamber near the main camp as part of research projects being conducted by camp officials.