Tuol Sleng Genocide Museum

The Tuol Sleng Genocide Museum, formerly known as Security Prison 21 (S-21), is a memorial site in Phnom Penh, Cambodia. It preserves evidence of a tragic period in Cambodian history, aiming to encourage visitors to be messengers of peace. The museum offers permanent and temporary exhibitions, guided tours, and educational programs to inform visitors about the atrocities committed during the Khmer Rouge era.

Planning your visit

Tuol Sleng was a school before the Khmer Rouge turned it into Security Prison 21, and the classrooms are still recognisable beneath the cell partitions and barbed wire. The museum, established in 1980, preserves the site largely as it was found: interrogation rooms, iron bed frames, and the photographic archive of prisoners the regime itself compiled. It is a demanding visit rather than a sightseeing stop, and the audio guide — narrated in part by survivors — is what most visitors say makes it comprehensible.

Almost every bookable option pairs Tuol Sleng with Choeung Ek, the killing field outside the city where prisoners were taken, because the two sites tell one sequence and are hard to understand separately. Half-day guided tours covering both are the standard format. Others extend into Phnom Penh's temples and the Royal Palace for a fuller day, and several combine the sites with airport transfers, which works well on arrival or departure days. Current departures are shown below.