Tuol Sleng Genocide Museum (S-21): Bearing Witness in Phnom Penh

Tuol Sleng in Phnom Penh was S-21, the Khmer Rouge detention and interrogation centre, set up in a former school. The museum says 15,000 to 20,000 people were imprisoned here, and twelve former inmates, including four children, survived.^[1] The site became a museum in 1979.^[1] The exhibits can be deeply distressing. Come with time for breaks rather than treating it as a quick sightseeing stop.

History of S-21

The school was built in 1962 as Preah Ponhea Yat High School and later renamed Tuol Svay Prey. In Lun, also known as Nath, was the first chief of S-21, followed by Duch in 1976.^[1]

Former classrooms became individual cells or communal detention rooms. People held here were interrogated and tortured, and the museum displays the instruments, shackles and chains.^[1][2]

S-21 and Choeung Ek belonged to the same system of detention and execution. Prisoners who survived torture were killed nearby at first, and later taken to the Choeung Ek killing field just outside the city.^[1] Visiting both helps you tell the place of detention from the execution site.

What You Will See

The museum occupies four main buildings, labelled A to D, plus the grounds around them.

Building A: The Detention Rooms

On the ground floor of Building A, a classroom was divided into two rooms to hold high-ranking Khmer Rouge cadres accused of treason, who were kept in single cells and chained to iron beds.^[1] Paintings by the S-21 survivor Vann Nath hang here.^[2]

Building B: Photographs

In Building B, the cells have been removed to make space for the museum's most haunting exhibit: photographs of the thousands of people who lost their lives at S-21.^[1] They show men, women, elderly people, teenagers and children. Some look terrified, some confused, some stare straight at the camera with expressions that are impossible to read.

Take time with the photographs and pause when you need to. These are records of real people. Choose a pace that gives you room to reflect, and do not feel you have to look at every image.

Building C: The Cells

Building C is preserved exactly as it was during the Khmer Rouge period.^[2] Classrooms are divided into small cells, where family members were chained.^[1] The cells measure 0.8 by 2 metres, barely large enough to lie down in.^[1] They give a visceral sense of the confinement prisoners endured.

Building D: History and Context

Building D displays the torture instruments used by S-21's interrogators.^[1] Vann Nath's paintings in Buildings A, B and D depict scenes of torture and the living conditions in the prison.^[2]

For the wider legal context, the Extraordinary Chambers in the Courts of Cambodia (ECCC) state that over a million people were killed or perished in Democratic Kampuchea. Its investigations and court proceedings ran from 2006 to 2022, and since January 2023 it carries out residual functions such as victim and witness protection, supervising the enforcement of sentences and giving the public access to documents.^[3]

Survivor Talks

The museum runs a testimony program called "Childhood without color" every Monday, Wednesday and Friday, except national holidays, from 14:30 to 15:00. Ask at the museum on the day.^[4]

Visiting Tuol Sleng

Tickets and Hours

Tickets are sold only at the entrance booth, in cash, in Cambodian riel or US dollars. Foreign visitors with a K-VISA enter free and must show the K-VISA confirmation. The audio guide is available in Khmer, English, French, German, Chinese, Vietnamese, Korean, Japanese, Spanish, Dutch and Italian. Personal guides speak Khmer and English and work for a contribution.^[4]

The ground floors of all buildings are wheelchair-accessible, while upper floors are reached only by stairs, so ask staff for help. Strollers are not allowed inside the exhibition buildings.^[4] Cover your arms and legs, as is customary at Cambodian commemorative and religious sites.^[4]

Getting There

The museum is on Street 113 in Boeng Keng Kang III, Phnom Penh.^[4] Show the address to your driver or app, and agree whether waiting time and the return trip are included before you set off.

How Long to Spend

Allow a few hours, with extra time for breaks, the documentary or the testimony program. Check those times before you plan your onward journey.

Combining with the Killing Fields

A visit to Choeung Ek complements Tuol Sleng: one tells the story of S-21 detention, the other of its execution site. UNESCO lists both among the Cambodian Memorial Sites.^[5] Check each site's hours and admission separately, and agree the route, waiting time and return journey with your driver before departure.

Visiting both sites in one day is emotionally heavy. Some travellers spread them across two days with lighter activities in between. There is no wrong approach, but be prepared for the cumulative impact.

Tips for Visiting Tuol Sleng

• Prepare emotionally. This is not a typical tourist attraction. The content is graphic and deeply distressing. Read about the Khmer Rouge beforehand for context, and give yourself permission to take breaks in the courtyard.
• Use the audio guide. The exhibits are powerful on their own, and the audio guide adds context, personal stories and historical detail.
• Arrive when the museum opens. It opens at 08:00, and an early start leaves room for the exhibits and for breaks.^[4]
• Respect the photography rules. Photographs for non-commercial personal or research use are permitted, and commercial work needs permission. Using mobile phones inside the exhibition buildings and flying drones without authorization are prohibited.^[4]
• Think about children. The museum warns that its exhibits may not be appropriate for visitors aged 14 and younger.^[4]
• Allow time afterwards. Many visitors need quiet time to process the experience. Plan a low-key activity for the rest of the day, whether a walk along the riverfront, a cafe or a return to your hotel.

Tuol Sleng exists so that what happened here is not forgotten. Visiting is an act of witness. For more on Phnom Penh's historical sites and planning your time in Cambodia, GoAsia.cc has comprehensive guides.