Tuol Sleng Museum – Phnom Penh

In 1975 Tuol Svay Prey High School was taken over by Pol Pot's security forces and turned into a prison know as Security Prison 21 (S-21). It soon became the largest such center of detention and torture in the country. Almost all of the people held at S-21 were later taken to the extermination camp at Choeung Ek, southwest of the capital, and executed. Detainees who died during torture were buried in mass graves inside the prison grounds. During the first part of 1977, S-21 claimed a average of 100 victims per day.