After Cambodia secured independence from France in 1952, the country struggled through decades of instability, due in no small part to parallel events in Vietnam. In 1975, the government fell under the control of the Khmer Rouge, an idiosyncratic communist movement led by Saloth Sar, better known by his nomme de guerre Pol Pot (pictured at left). The avowedly anti-intellectual regime declared Year Zero to mark the end of all that had come before, sealed off the country from the outside world, ordered the emptying of cities, and began a purge of perceived political opposition. Approximately three million people, or one in five citizens, were killed between 1975 and 1979, when Vietnamese forces ousted the Khmer Rouge. The images here, taken by the author in 2010, show the memorial at the best known of the ‘killing fields,’ Choeung Ek, and the former Tuol Sleng detention center in Phnom Penh, also known as S-21.