Auschwitz concentration camp (German: Konzentrationslager Auschwitz (pronounced [kɔntsɛntʁaˈtsi̯oːnsˌlaːɡɐ ˈʔaʊʃvɪts] (listen)); also KL Auschwitz or KZ Auschwitz) was a complex of over 40 concentration and extermination camps operated by Nazi Germany in occupied Poland (in a portion annexed into Germany in 1939) during World War II and the Holocaust. It consisted of Auschwitz I, the main camp (Stammlager) in Oświęcim; Auschwitz II-Birkenau, a concentration and extermination camp with gas chambers; Auschwitz III-Monowitz, a labor camp for the chemical conglomerate IG Farben; and dozens of subcamps.