The huge Birkenau camp (same hours as Auschwitz) was designed as a death camp in 1942, when the Nazis decided on their policy of exterminating European Jewry. Allow 1–2 hours to fully explore the 175-hectare site. Large gas chambers at the back of the camp were damaged but not destroyed by the fleeing Nazis in 1945. Victims arrived in closed trains, and those who were fit to work (around 25 percent) were immediately separated from those who were driven straight to the gas chambers. The railway line is still there, just as the Nazis abandoned it. One of the few buildings still standing here is the so-called “Sauna”, where the newly arrived were undressed, shaved and assigned camp clothes – a matter-of-fact museum display takes you methodically through the process.