AUSCHWITZ-BIRKENAU

The Auschwitz concentration camp complex was the largest of its kind established by the Nazi regime. It included three main camps. All three camps used prisoners for forced labor. One of them also functioned for an extended period as a killing center. The camps were located approximately 37 miles west of Krakow. They were near the prewar German-Polish border in Upper Silesia, an area that Nazi Germany annexed in 1939 after invading and conquering Poland. 
The SS authorities established three main camps near the Polish city of Oswiecim: Auschwitz I in April 1940; Auschwitz II (also called Auschwitz-Birkenau) in October 1941; and Auschwitz III (also called Auschwitz-Monowitz) in October 1942.