The Tuol Sleng Genocide Museum (Khmer: សារមន្ទីរឧក្រិដ្ឋកម្មប្រល័យពូជសាសន៍ទួលស្លែង, romanized: Saromontir Ukredth Kamm Braly Pouchsasa Tuol Sleng) or simply Tuol Sleng (Khmer: ទួលស្លែង, Tuŏl Slêng [tuəl slaeŋ]; lit. "Hill of the Poisonous Trees" or "Strychnine Hill") is a museum chronicling the Cambodian genocide. Located in Phnom Penh, the site is a former secondary school which was used as Security Prison 21 (S-21; Khmer: មន្ទីរស-២១) by the Khmer Rouge regime from 1975 until its fall in 1979.

Cambodia's Tuol Sleng Genocide Museum Inside Tour in Phnom Penh