Tuol Svay Prey High School in central Phnom Penh was converted into a detention and torture center in 1975 by the Khmer Rouge and became the notorious Security Prison 21 (S-21).
Over 17,000 people held at S-21 were later executed at the Cheung Ek Killing Field. Those who died during their interrogation were buried in mass graves in the prison grounds. Seven prisoners were found alive at S-21 when the Vietnamese army liberated Phnom Penh in early 1979. Fourteen others had been tortured to death as Vietnamese forces were closing in on the city.
The museum’s entrance is on the western side of Street 113 St north of Street 350. Open daily from 7 to 11.30 am and from 2 to 5.30 pm. Cost is US$2. A grim and disturbing place but important as a memory of the suffering of the Cambodian people and a testament to the murderous Khmer Rouge.