Although there were a large number of Nazi concentration camps, the one that since World War II has come to represent them all and act as a symbol of the atrocity of the Holocaust is Auschwitz-Birkenau, whose remains continue to be visited by many thousands of tourists every year. Situated just outside the Polish town of Oswiecim, near Krakow, Auschwitz-Birkenau is also the largest mass murder site documented anywhere in history. Established first in May 1940 on territory occupied by Germany at the onset of World War II, Auschwitz soon emerged as the central killing center for Jews murdered by National Socialism and its allies. In less than five years some 1.1 million victims perished, overwhelmingly Jews, but also 75,000 Poles, 25,000 Roma and Sinti travelers, 15,000 Soviet POWs, and thousands of others—including many clergy and other persons opposed to Nazism on conscientious grounds. Its sheer size, slave labor facilities, and its bureaucratic management of genocide have made Auschwitz a central—often exemplary—part of the Holocaust story.
Finally, Nazi population policy— especially following the invasion of the USSR in June 1941—grew more intense and ambitious toward “undesirable elements.” By the summer of 1941, Russian prisoners quickly outnumbered surviving Polish workers at Auschwitz, receiving even worse treatment and being worked to death at even greater rates: of nearly 12,000 laborers, only 150 Russian POWs survived their first year building Auschwitz. In a related development for “solving” Nazism’s “demographic problems,” Russian POWs were also the first group gassed by the pesticide Zyklon-B, in September 1941, at the initiative of Höss’s deputy, Karl Fritsch, in the infamous punishment cells of Block 11. Previous attempts at mass murder by the Third Reich through shooting, explosives, injections, and carbon monoxide tanks and engine fumes were all superseded by the efficiency and availability of Fritsch’s successful experiment with Zyklon-B.