Toul Sleng Genocidal Museum is the former Toul Sleng High School. In 1975, during the Khmer Rouge regime, the school was used as a prison and torture center, known as the time as S-21. Thousands of Cambodian and a number of foreigners were housed and tortured there until they were executed. Today the site is a museum, where visitors can walk among some of the cells and look at the photos of hundreds of people who died there. There are also paintings, painted by artist Vann Vath, a former prisoner, that depict the torture of prisoners.