Museums thumb|Skulls displayed in the memorial tower The Tuol Sleng Museum of Genocide is a former high school building, which was transformed into a torture, interrogation and execution center between 1976 and 1979. The Khmer Rouge called the center S-21. Of the estimated 15,000 to 30,000 prisoners, only seven prisoners survived. The Khmer Rouge photographed the vast majority of the inmates and left a photographic archive, which enables visitors to see almost 6,000 S-21 portraits on the walls. Visitors can also learn how the inmates were tortured from the equipment and facilities exhibited in the buildings.
Museums thumb|Skulls displayed in the memorial tower The Tuol Sleng Museum of Genocide is a former high school building, which was transformed into a torture, interrogation and execution center between 1976 and 1979 The Khmer Rouge called the center S-21. Of the estimated 15,000 to 30,000 prisoners, only seven prisoners survived. The Khmer Rouge photographed the vast majority of the inmates and left a photographic archive, which enables visitors to see almost 6,000 S-21 portraits on the walls. Visitors can also learn how the inmates were tortured from the equipment and facilities exhibited in the buildings.