Sunlight streams into a former classroom that has been converted into individual detention cells at Tuol Sleng prison in Phnom Penh, Cambodia. Prisoners generally spent two to three months at Tuol Sleng, where they were tortured and made to confess to a list of crimes against the Khmer Rouge regime. High-ranking party officials who had been purged were often held longer. After their incarceration, all but a handful of the 17,000 people who passed through Tuol Sleng were murdered in the Killing Fields. March 1, 2012.