An aerial reconnaissance photograph of Auschwitz concentration camp in Poland, showing Auschwitz II (Birkenau Extermination Camp), 21st December 1944. It is one of a series of aerial photographs taken by Allied reconnaissance units under the command of the 15th US Army Air Force during missions dating between April 4, 1944 and January 14, 1945. The photos were used to plan bombing raids, determine the accuracy of bombing sorties, or make damage assessments. (Photo by Galerie Bilderwelt/Getty Images)