Tuol Sleng Genocide Museum, also known as S-21, is a haunting reminder of Cambodia's tragic history during the Khmer Rouge regime. Located in the heart of Phnom Penh, this former high school was transformed into a prison and interrogation center from 1975 to 1979. Visitors can explore the preserved buildings, which now serve as a museum dedicated to the victims of the genocide. The museum houses a collection of photographs, personal belongings, and testimonies that tell the stories of those who suffered. Walking through the somber halls, one can feel the weight of history and the resilience of the Cambodian people. The museum also features a memorial stupa filled with the skulls of victims, serving as a poignant tribute to those who lost their lives. Guided tours are available, providing deeper insights into the events that unfolded here. The museum is not only a place of remembrance but also a vital educational resource for understanding the consequences of totalitarianism. A visit to Tuol Sleng is essential for anyone seeking to grasp the complexities of Cambodia's past.