#1 Tuol Sleng Genocide Museum (Phnom Penh)
The Tuol Sleng Genocide Museum is a former school in downtown Phnom Penh, converted into a detention and torture center by the Khmer Rouge. Preserved exactly as it was found on January 7, 1979, the site comprises four buildings enclosing a schoolyard.
Visiting is difficult and not recommended for children or sensitive visitors. You will see the direct results of human cruelty and the horrors of a regime that lost its way.