This former school was used as the notorious Security Prison 21 (S-21) by the Khmer Rouge. It's estimated that all but seven of the 20,000 prisoners sent here were executed. Many were tortured.
Prisoners were hung painfully from the hooks on this frame. If they didn't answer questions satisfactorily, then they'd be dunked upside down into the water-filled pots below.
The Khmer Rouge were obsessed with documenting their activities. These are photographs of the young men - many just teenagers - who were guards here. Each of the prisoners was also photographed upon entry.
Just some of the shackles used on Tuol Sleng's prisoners.
Busts of Khmer Rouge leader, Pol Pot.
These are the graves of the bodies found when invading Vietnamese forces entered Tuol Sleng, after the Khmer Rouge had fled.