It was once Tuol Svay Prey High School, before the complex's five buildings were cleared for their new role in 1975. The complex was renamed Security Prison 21 (S-21), barbed wire was added to the perimeter, and the windows were fortified with iron bars.
All the classrooms were transformed into prison cells and interrogation chambers. Each building has three floors at most. The bottom floor housed the smallest cells, each holding a single prisoner chained to the floor. Women were confined to the second floor. The third floor were mass prison cells, holding large groups chained to long iron bars.
Ostensibly prisoners were brought here to be imprisoned and interrogated. The unspeakable torture that went on here meant that the prisoners would confess to anything. School boys confessed to being agents of the CIA, housewives made up stories about their neighbors... not even Communist higher-ups were immune from this treatment.
S-21 is in Tuol Svay Prey sub-district, south of the capital Phnom Penh. The graves of Tuol Sleng's last victims precede the visitor entering the complex. After paying the entrance fee, you can walk through by yourself, or get a guide to accompany you. We suggest you do the latter - Tuol Sleng is almost unremittingly grim, and you'll need someone to put all the death and pain in context.
The horrible genius of the Khmer Rouge lay in their attention to detail. Prisoners were photographed and interrogated on their life details before being chained to their cells. This impersonal collection of data is presented to the visitor, room after room full of photographs of doomed men, women, and children, a glimpse of the estimated 20,000 prisoners who entered Tuol Sleng.
The prisoners were overwhelmingly Cambodian, although the prison did see its share of Americans, British, and Australians. The twisted ideology of the Khmer Rouge meant that anybody with an education, anybody who wasn't from around there, even anybody who wore glasses was suspect, and could (and often did) end up screaming their lives out in Tuol Sleng.
You'll also see a torture chamber, left in almost the same condition as they were found by the Vietnamese invaders who kicked the Khmer Rouge out in 1979. The torture devices are also present, with detailed explanations on how they were used.
The end result of these devices is also nearby - cases of skulls belonging to S-21's unfortunate victims. (Tuol Sleng's most grisly attraction, a "skull map" of Cambodia in 300-plus skulls, was dismantled in 2002. )
The Vietnamese found Tuol Sleng by following the stench of decay. When they arrived, they found only seven prisoners alive (just barely), and several other less fortunate folk chained to iron beds, only recently killed by the escaping Khmer Rouge.
For many years afterward, the orphanages in Cambodia were filled with child survivors of the Khmer Rouge carnage in Tuol Sleng.
Tuol Sleng Genocide Museum
Street 113, Phnom Penh
Phone: +855 23 30 0698
Operating Hours: 7a–11:30a, 2p–5:30p
Getting there: a taxi, moto, or cyclo can take you there from your Phnom Penh hotel. Admission is US$2, paid at the booth just inside the gate.