Unidentified Cambodian prisoner at S-21 prison in Phnom Penh. The prison photographer Nhem Ein said the number 321 meant he was the 321st person photographed that day. Only seven people from nearly 30,000 people survived Pol Pot's brutal prison, which was created to eliminate both real and imagined enemies of the communist Khmer Rouge. Photo: © Tuol Sleng Museum of Genocide