Gas Chamber and Crematorium II / Krema II of Auschwitz-Birkenau

One of the largest mass murder sites in the history of mankind operated from here. Although it was functional from March, 1943 to November, 1944 an estimated 500,000 plus Jews were gassed to death at this very site using cyanide-based insecticide Zyklon B. The complex consisted of an undressing room, an underground gas chamber, a crematorium with five ovens for burning corpses and rooms for the SS officers. Here is a virtual reconstruction of crematorium II from YouTube.The whole complex was dynamited by the Nazis on January 20, 1945, left to the ruins as seen today. The underground gas chamber room is still partially intact.