Most travel stories are of the happy-go-lucky variety. Every once in a while, however, one visits a place that evidences the vicious, dark side of mankind. Khmer Rouge Prison 21, known as Tuol Seng, is one such place. It is a stark reminder of the cruelties humanity can visit upon itself. Tuol Sleng In 1962, the high school of Ponhea Yat was opened in the center of Phnom Pehn. The school consists of three buildings in a horseshoe layout with each building having three stories. In the 1970s,.