A professional English speaking tour guide will pick you up from your hotel and drive you to the killing fields of Choeung Ek Genocide Center – 9 miles away south of Phnom Penh. The infamous killing fields have a bloody history. Once an orchard and a Chinese cemetery, the Khmer Rouge, lead by Pol Pot, turned the place into what became known as the killing fields, where they executed around 20.000 victim. Over three years, they massacred and buried 2.5 million people. After remembering the dead, return to Phnom Penh to visit Tuol Sleng Genocide Museum (S21). Meaning hill of the poisonous trees, Pol Pot turned a once popular high school into a high security prison. 20,000 people were imprisoned there, many of whom were tortured for information. Today it serves as a museum and a reminder of darker days.