The Tuol Sleng Genocide Museum is the memorial site of the S-21 interrogation and detention center of the Khmer Rouge regime. Located in the heart of Phnom Penh, it preserves a tragic period in history with the aim to encourage visitors to be messengers of peace. Tuol Sleng Genocide Museum is the memorial site of “Security Office 21” (S-21) of Democratic Kampuchea (also known as the Khmer Rouge regime) and located in what was then the abandoned city of Phnom Penh, whose citizens had been evacuated on 17 April 1975. S-21 served as the central hub of a vast prison system throughout the country and was used throughout the period as a secret facility for the detention, interrogation, torture and extermination of those deemed “political enemies” of the regime. Due to a policy of guilt-by-association, at times whole families were detained at the center. Only 12 former inmates survived the opening of S-21 when Phnom Penh was liberated. Four of them were children.