In the middle of Phnom Penh, behind an unassuming entrance on Street 113, stands a place that tells one of the darkest chapters in Cambodia's modern history.
This is the Tuol Sleng Genocide Museum, the former S-21 prison and interrogation center of the Khmer Rouge regime.
Today, classrooms, corridors, photographs, prison cells and surviving evidence have been preserved as a memorial and museum.
Visiting Tuol Sleng is not the same as visiting a palace, temple or traditional museum. It is a place for remembering, learning and reflection.
For travelers visiting Phnom Penh, understanding this part of Cambodia's history can add important context to the country you see today.
Tuol Sleng Genocide Museum at a Glance
| Information | Details |
|---|---|
| Name | Tuol Sleng Genocide Museum |
| Former name | S-21 Security Prison |
| Location | Phnom Penh, Cambodia |
| Address | Street 113, Boeung Keng Kang III |
| Opening hours | Every day, 8:00 AM–5:00 PM |
| International adult ticket | US$5 |
| International children 10–17 | US$3 |
| Children under 10 | Free |
| Cambodian citizens | Free |
| Payment | Cash – Cambodian riel or US dollars |
| Recommended visit | Around 1.5–2.5 hours |
| Type of attraction | Museum and memorial |
| Best for | History, education and reflection |
| Photography | Follow museum rules and be respectful |
| Nearby | Independence Monument, BKK, Russian Market |
The museum's official visitor information confirms that it is open every day from 8:00 AM to 5:00 PM and currently charges international adults US$5, visitors aged 10–17 US$3, and children under 10 free.
What Is Tuol Sleng Genocide Museum?
Tuol Sleng Genocide Museum is located on the site of the former S-21 interrogation and detention center operated during the Khmer Rouge period.
Before becoming S-21, the site was a secondary school.
The buildings were transformed into a prison complex after the Khmer Rouge took control of Phnom Penh in 1975.
Today, the former school has been preserved as a memorial and historical museum.
The museum's purpose is not simply to display old objects. Its mission includes preserving the memory of victims, presenting historical evidence and encouraging education and reflection so that such violence is not repeated.
The History of Tuol Sleng
Before S-21
The site originally served as a school in Phnom Penh.
Its buildings were designed for education, with classrooms and open spaces.
During the Khmer Rouge period, however, the location was transformed into one of the regime's most notorious security centers.
S-21 During the Khmer Rouge Period
Between 1975 and 1979, Democratic Kampuchea established a nationwide system of security centers, prisons and execution sites.
S-21 became the regime's central detention and interrogation facility.
Prisoners were detained, interrogated and tortured there. Many were eventually transferred to the Choeung Ek killing site outside Phnom Penh.
UNESCO states that more than 18,000 men, women and children were detained and murdered at S-21 according to the regime's records.
The prison also held people from different backgrounds, including Cambodian citizens and some foreign nationals.
What Happened to the Prisoners?
People sent to S-21 were often accused of being enemies of the regime.
In many cases, prisoners were forced to provide confessions during interrogation.
The museum preserves documents, photographs and other evidence from this system.
The former prison records provide an unusually detailed documentary record of the people who passed through S-21.
UNESCO's Memory of the World documentation notes that the archive includes photographs of more than 5,000 prisoners as well as confessions, biographies and other records.
What Happened When the Khmer Rouge Left Phnom Penh?
The Khmer Rouge lost control of Phnom Penh on 7 January 1979.
The S-21 site was subsequently preserved rather than demolished.
It became a museum and memorial to document what happened there.
UNESCO notes that Tuol Sleng was established as a museum in 1979 on the former S-21 site and that the buildings and cells were preserved after the end of Khmer Rouge rule.
This is one reason the site remains such an important historical place.
Visitors can still see many of the original structures rather than simply looking at a modern exhibition about the past.
What Can You See Inside Tuol Sleng?
The museum's permanent exhibition contains historical evidence connected with S-21 and the Khmer Rouge period.
Visitors can see:
- Prison cells
- Prisoner photographs
- Documents
- Shackles and chains
- Prisoners' clothing
- Interrogation-related objects
- Paintings by survivor and artist Vann Nath
- Memorial spaces
- Preserved buildings
The museum states that Building C has been preserved as it was during the Khmer Rouge period, while Buildings A, B and D contain parts of the permanent exhibition.
The Prisoner Photographs
One of the most memorable parts of the museum is the collection of photographs of prisoners.
The photographs were taken as part of the prison's record-keeping system.
Looking at the faces makes the history feel much more personal.
These aren't simply statistics in a history book.
They are photographs of individual people who were imprisoned at S-21.
The museum preserves thousands of these records, making the photographic archive an important part of its historical documentation.
Building C
Building C is particularly distinctive because the structure has been preserved as it was during the prison period.
Classrooms were divided into smaller cells.
The contrast can be difficult to process.
A building originally intended for education had been converted into a place of detention.
The museum asks visitors to observe these spaces respectfully rather than treating them simply as unusual photo opportunities.
Vann Nath's Paintings
The museum also displays paintings by Vann Nath, one of the few known survivors of S-21 and a prominent Cambodian artist.
His paintings depict experiences of imprisonment, torture and life inside the prison.
They provide another perspective on the history—one based on the memory of someone who personally survived S-21.
The museum includes his paintings within its permanent exhibition.
The Tuol Sleng Archives
Tuol Sleng is also important because of its extensive archive.
The collection includes:
- Photographs
- Prisoner records
- Confessions
- Biographical information
- Khmer Rouge documents
- Prison records
- Other historical materials
The archives were added to the UNESCO Memory of the World Register in 2009. UNESCO describes them as an important source of historical evidence and testimony.
The museum's collection has also been digitized to help preserve and provide access to historical records.
Tuol Sleng and UNESCO
There are actually two important UNESCO connections.
UNESCO Memory of the World
The Tuol Sleng Genocide Museum Archives were inscribed on the UNESCO Memory of the World Register in 2009.
UNESCO World Heritage
In July 2025, the Cambodian Memorial Sites were added to the UNESCO World Heritage List.
The serial World Heritage property includes:
- Former M-13 prison in Kampong Speu
- Tuol Sleng Genocide Museum in Phnom Penh
- Choeung Ek Genocidal Center
Together, the sites document different stages of the Khmer Rouge security system.
This makes Tuol Sleng part of a broader Cambodian memorial landscape rather than an isolated historical site.
Where Is Tuol Sleng Genocide Museum?
The museum is located in Boeung Keng Kang III, Phnom Penh.
Address
Street 113, Boeung Keng Kang III, Phnom Penh, Cambodia
The museum is close to central Phnom Penh and can be reached relatively easily by:
- Tuk-tuk
- Taxi
- Ride-hailing apps
- Private car
- Motorcycle
The official museum lists its entrance around Street 113 / Street 350.
Tuol Sleng Opening Hours
Every day
8:00 AM – 5:00 PM
The museum states that it remains open every day, including public holidays.
TravelKH Tip
Don't arrive five minutes before closing.
Give yourself enough time to walk through the buildings without rushing.
Tuol Sleng Entrance Fee
The current official admission prices are:
| Visitor | Admission |
|---|---|
| Cambodian citizen | Free |
| International adult, 18+ | US$5 |
| International child, 10–17 | US$3 |
| Child under 10 | Free |
| Foreign visitor with K-VISA | Free, with required confirmation |
The museum currently accepts cash in Cambodian riel or US dollars.
Audio Guide
The official museum information lists the audio guide at:
- Cambodian citizen: US$1
- Non-Cambodian citizen: US$5
A personal guide is listed as contribution-based.
How Long Do You Need at Tuol Sleng?
Allow approximately:
1.5–2.5 hours
You can walk through more quickly, but this is not a place where rushing makes much sense.
Take time to read the information.
Look at the photographs.
Understand the sequence of events.
Pause when you need to.
If you are particularly interested in Cambodian history, you may want to spend longer.
What Is the Best Time to Visit?
Because Tuol Sleng is indoors and outdoors, you can visit throughout the day.
However, for a more comfortable itinerary:
Morning: 8:00–10:30 AM
A good option if you want to continue sightseeing afterward.
Midday: 11:00 AM–2:00 PM
Useful if you're already exploring central Phnom Penh, although the outside temperature can be hot.
Afternoon: 2:00–4:00 PM
Another good option, particularly if you want to combine the museum with nearby attractions.
TravelKH Recommendation
For most travelers, morning or early afternoon works well.
Is Tuol Sleng Suitable for Children?
This depends heavily on the child's age and maturity.
Tuol Sleng deals directly with:
- Imprisonment
- Torture
- Death
- Genocide
- Historical trauma
The museum's exhibits can be emotionally difficult.
Parents should consider the child's age and ability to understand the subject before visiting.
The museum itself has an admission category for children aged 10–17, but a ticket policy should not be interpreted as a recommendation about whether a particular child is emotionally ready for the content.
What Should You Wear?
There isn't a strict temple-style dress code, but respectful clothing is strongly recommended.
The museum specifically asks visitors to dress appropriately out of respect for victims and notes that shorts and sleeveless shirts are not considered respectful attire at memorial and religious sites in Cambodian culture.
A simple choice is:
- T-shirt or shirt with sleeves
- Long trousers or longer shorts
- Comfortable shoes
Photography at Tuol Sleng
Visitors may want to take photographs because the preserved buildings are historically significant.
But remember:
This is a memorial site, not a photo attraction.
Avoid posing in ways that make the location look like a theme park or entertainment venue.
Do not photograph other visitors without permission.
Follow signs and museum instructions regarding photography.
Most importantly, take a moment to understand what you're photographing.
Can You Visit Tuol Sleng and Choeung Ek on the Same Day?
Yes.
In fact, many travelers combine the two.
Morning
Tuol Sleng Genocide Museum
↓
Lunch
↓
Afternoon
Choeung Ek Genocidal Center
The two locations tell different parts of the same historical system.
Tuol Sleng was a detention and interrogation center.
Choeung Ek was one of the execution sites associated with S-21.
UNESCO's description of the Cambodian Memorial Sites specifically identifies Tuol Sleng as the former S-21 prison and Choeung Ek as its associated execution site.
Suggested Phnom Penh Genocide History Day
If this is your first visit to Phnom Penh and you want to understand Cambodia's recent history, you could plan:
8:30 AM
Arrive at Tuol Sleng
8:30–11:00 AM
Explore the museum
11:30 AM
Lunch and break
1:00 PM
Travel to Choeung Ek
1:30–3:00 PM
Visit Choeung Ek
3:00 PM onward
Return to central Phnom Penh
Afterward, give yourself some quiet time rather than immediately moving into a packed sightseeing schedule.
Tuol Sleng vs Choeung Ek
| Tuol Sleng | Choeung Ek | |
|---|---|---|
| Location | Phnom Penh city | Outside central Phnom Penh |
| Former use | S-21 detention/interrogation center | Execution site associated with S-21 |
| Main focus | Prisoners, interrogation and prison system | Execution site and memorial |
| Main experience | Buildings, photographs, documents and cells | Memorial grounds and historical evidence |
| Recommended time | 1.5–2.5 hours | Around 1–2 hours |
| Best combined? | Yes | Yes |
Together, the two sites help visitors understand different stages of the S-21 system.
What Else Is Nearby?
Tuol Sleng is in a central part of Phnom Penh, so you can easily combine your visit with other attractions.
Consider visiting:
Independence Monument
A major Phnom Penh landmark located a short distance from the museum.
Royal Palace & Silver Pagoda
Important attractions for understanding Cambodia's royal history.
National Museum of Cambodia
A useful stop for Cambodian art and history.
Russian Market
Good for food, shopping and souvenirs.
Phnom Penh Riverside
A relaxing place to walk after a day of sightseeing.
Suggested Half-Day Phnom Penh Itinerary
If you want to combine history with a more relaxed experience:
8:30 AM – Tuol Sleng Genocide Museum
↓
11:00 AM – Lunch
↓
12:30 PM – Independence Monument
↓
1:00 PM – Royal Palace / Silver Pagoda
↓
3:00 PM – National Museum
↓
5:00 PM – Phnom Penh Riverside
This gives you a mixture of Cambodia's recent history, royal heritage, art and modern city life.
Tips for Visiting Tuol Sleng
1. Don't rush
The museum contains a lot of information.
2. Read the background information
Understanding the historical context makes the visit much more meaningful.
3. Consider an audio guide
The museum officially offers an audio guide for international visitors.
4. Bring water
Phnom Penh can be hot, particularly when walking between buildings.
5. Dress respectfully
Remember that this is a memorial to victims.
6. Be prepared emotionally
Some exhibits are disturbing.
7. Don't treat it like a normal tourist attraction
Photography and sightseeing should never take priority over respect.
A Note for First-Time Visitors
If you know very little about Cambodian history, don't worry.
You don't need to be an expert before arriving.
It may actually be useful to learn just a little about the period beforehand:
1975–1979 – Khmer Rouge / Democratic Kampuchea period
Then the exhibits will make more sense as you move through the museum.
You can also visit with a guide or use the museum's audio guide to understand the historical context.
Why Is Tuol Sleng Important Today?
The importance of Tuol Sleng goes beyond the physical buildings.
The museum preserves evidence of people who were imprisoned there and helps document what happened during one of the most devastating periods in Cambodia's history.
Its mission specifically emphasizes preserving memory, education and preventing the recurrence of genocide and violence.
UNESCO's 2025 World Heritage inscription also recognizes the broader Cambodian Memorial Sites as places of remembrance, education and reflection.
For visitors, that means Tuol Sleng isn't simply somewhere to "see."
It is somewhere to understand.
Frequently Asked Questions
What is Tuol Sleng Genocide Museum?
It is a museum and memorial located at the former S-21 detention and interrogation center of the Khmer Rouge regime in Phnom Penh.
How much is Tuol Sleng?
International adults aged 18 and above currently pay US$5. Children aged 10–17 pay US$3, while children under 10 and Cambodian citizens enter free.
What time does Tuol Sleng open?
It is open every day from 8:00 AM to 5:00 PM.
Where is Tuol Sleng Genocide Museum?
It is on Street 113 in Boeung Keng Kang III, Phnom Penh.
How long should I spend at Tuol Sleng?
Around 1.5–2.5 hours is a reasonable amount of time for most visitors.
Is Tuol Sleng suitable for children?
The subject matter is very difficult and includes violence, imprisonment and death. Parents should decide based on the individual child's age and maturity.
Can I take photos?
Photography should always follow the museum's rules and be done respectfully.
Is Tuol Sleng a UNESCO World Heritage Site?
Yes. Since July 2025, Tuol Sleng has been part of the UNESCO World Heritage-listed Cambodian Memorial Sites, together with the former M-13 prison and Choeung Ek Genocidal Center.
Is Tuol Sleng the same as Choeung Ek?
No. Tuol Sleng was the S-21 detention and interrogation center. Choeung Ek was an associated execution site. They are separate locations but are historically connected.
Can I visit both in one day?
Yes. Visiting Tuol Sleng in the morning and Choeung Ek in the afternoon is a common way to understand the connected history of the two sites.
Final TravelKH Tip
Cambodia is famous for Angkor Wat, tropical islands, beautiful temples and delicious food.
But Cambodia's story is much bigger than its tourist highlights.
A visit to Tuol Sleng Genocide Museum gives travelers an opportunity to understand one of the most difficult periods in the country's recent history.
Don't come here looking for entertainment.
Come to learn.
Walk slowly.
Read the stories.
Look at the photographs.
And remember that behind every number in a history book were real people and families.
Tuol Sleng is a difficult place to visit, but understanding its history can help travelers better understand Cambodia today.
Official site: https://tuolsleng.gov.kh/en/
