Between the years 1942-1944 it became the main mass extermination camp where Jews were tortured and killed for their so-called racial origins. Auschwitz Birkenau was the largest of the concentration camp complexes created by the Nazi German regime and was the one which combined extermination with forced labour. The Auschwitz Birkenau camp complex comprises 155 brick and wooden structures (57 in Auschwitz and 98 in Birkenau) and about 300 ruins. Most of the victims of the Auschwitz complex, probably about 90%, were killed in the Birkenau camp. AuthenticityThe Auschwitz camp complex has survived largely unchanged since its liberation in January 1945.