C5-3
Cell complex in the Tuol Sleng Museum the former Tuol Svay Prey High school that in '75 till '79 was used by Pol Pot's Khmer Rouge Secret Service as Prison S-21 in Phnom Penh in Cambodia
More than 17.000 prisoners passed through S-21 to be questioned tortured and photographed, before clubbed dead (to save expensive bullets) at the notorious "Killing Fields" from the extermination camp at Choeung Ek.