Phnom Penh Killing Fields and S21: Our Tour & What We Learned

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Visiting the Phnom Penh Killing Fields and S21 is certainly not a standard sightseeing activity. Walking into places like the Tuol Sleng Genocide Museum or traveling out to the Choeung Ek Genocidal Center demands a heavy emotional investment, and it is entirely normal to feel a sense of dread or hesitation before going.

Yet, sitting comfortably on a beach in Koh Rong Samloem or exploring the Angkor Wat temples only reveals one side of Cambodia. To truly understand this country, you have to look directly at the scars left behind by its recent past. If you’re still asking yourself is Phnom Penh worth it, confronting these heavy sites is ultimately what makes the capital so deeply important to experience.

This guide covers what to expect from visiting these memorials, how the logistics work, and the steps you can take to move through them with care. While confronting this dark chapter of history is difficult, bearing witness is a vital part of respecting the resilience of the Cambodian people and understanding modern Cambodia as a whole.

To navigate the logistics and ensure you don’t miss the deep historical context, we chose to join a guided excursion, and it made all the difference!

Our Top Pick

Our personal FAVOURITE tour is the Phnom Penh: The Killing Fields & Tuol Sleng Genocide Museum.

Exploring these sites with an expert guide makes all the difference.

Instead of just looking at exhibits, you get deeply moving historical context and personal testimonies that bring the tragic history to life.

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Understanding the History of Choeung Ek and S-21 Prison?

A Brief Historical Background on the Khmer Rouge Regime

Between 1975 and 1979, the Khmer Rouge regime led by Pol Pot imposed a radical agrarian revolution on Cambodia that turned the country into a forced labor camp. In an attempt to create a classless agrarian society, the regime emptied cities, abolished money, religion, and private property, and targeted intellectuals, minorities, monks, and in general, anyone suspected of opposition.

By the time Vietnamese forces and the Kampuchean United Front captured Phnom Penh in early 1979, an estimated 1.7 to 2 million people had died from execution, starvation, exhaustion, and lack of medical care.

The Connection Between Tuol Sleng (S-21 Prison) and the Killing Fields (Choeung Ek)

The atrocities committed under the regime followed a systematic, bureaucratic pipeline, of which Tuol Sleng and Choeung Ek represent two connected stages.

• Tuol Sleng (S-21): Originally a secondary school, this facility was converted into the regime’s premier secret interrogation center. Prisoners suspected of treason were brought here to be interrogated, tortured, and forced into signing false confessions before being condemned.

• Choeung Ek (The Killing Fields): Once prisoners at S-21 and other interrogation centers had been processed and “confessed,” they were loaded onto trucks and transported to execution sites like Choeung Ek on the outskirts of the city. Here, mass graves were dug to dispose of the victims.

The Phnom Penh Killing Fields and S21 Tour: Overview

Visiting these memorial sites independently involves navigating the 15-kilometer distance south to Choeung Ek, where return transport can be scarce. Also, having a knowledgeable guide ensures you absorb the profound historical context you would otherwise miss.

Below, we cover the complete tour details and every stop from the experience we did.

💡Important Note: This tour works because it covers the Killing Fields in the morning and ends your day at S-21 in the city center. Finishing centrally makes it much easier to decompress, grab a meal, and head back to your accommodation after an emotionally heavy experience.

Our Step-by-Step Experience: What We Saw, Learned, and Felt

Stop 1: Choeung Ek Genocidal Center (The Killing Fields)

We first met our tour guide and the rest of the group at the pick-up location we had chosen during the booking process. From there, our driver took us to the quiet memorial grounds of Choeung Ek (The Killing Fields). The site is relatively compact, so expect to spend about an hour here.

Our guide walked us across the grounds, pointing out the main monuments as well as sections of the path where fragments of clothing belonging to the victims can still occasionally be seen in the earth.

The most prominent monument on the site is the towering Memorial Stupa, which is filled with thousands of recovered skulls and artifacts. Scattered across the grounds are numerous marked mass graves.

One of the most harrowing sites is the Chankiri Tree, where soldiers executed infants. While confronting this reality is deeply painful, it reflects the true scale of the atrocities committed by the Khmer Rouge.

Another shocking stop in the fields was the storage room of chemical substances such as DDT. They used it to hide the smell of dead bodies from the people working near this field and also to kill those who had somehow survived the execution.

Listening to the tour guide detail individual testimonies while standing right where it all happened makes this chapter of Cambodia’s history unforgettable.

Note for independent travelers: If you visit on your own rather than joining a guided excursion, the site provides a comprehensive audio guide that is essential for understanding the history.

Stop 2: Tuol Sleng Genocide Museum (S-21)

Once we finished with the Choeung Ek Genocidal Center (the Killing Fields), we returned to the city center of Phnom Penh for the final and most painful part of the tour: the Tuol Sleng Genocide Museum (S-21 Prison).

Originally the Tuol Svay Prey High School, this site was converted into the regime’s premier security office under the direct command of the Communist Party of Kampuchea.

Anyone brought to S-21 was not expected to survive, as the regime targeted anyone deemed an “enemy of the revolution”, including officials of the previous government, intellectuals, foreigners, and eventually even purged members of the Khmer Rouge.

Out of more than 18,000 documented people who passed through these gates, only 12 people survived: 4 children and 8 men. Right after entering the premises of the former prison, you’ll be be meeting the looks of those who made it out of there alive

Walking into the former school buildings is an intensely haunting experience. Our guide walked us through structures like Building A, which contains high-security cells originally used for jailing, interrogating, and torturing high-ranking officials.

The former classrooms in Building B still hold the stark, chilling evidence of what happened behind closed doors: rusted iron bed frames, heavy shackles, ammo boxes used as crude toilets, and concrete or brick partitions hastily built to subdivide the rooms into suffocating solitary cells.

As you move through the blocks, you encounter room signs marking historic details, such as the cell belonging to Chum Mey, one of the 8 known adult survivors.

Other exhibits display rooms filled with haunting, floor-to-ceiling black-and-white identification photographs of prisoners staring down from the walls… Men, women, and children whose faces capture the final months of their lives.

A particularly heartbreaking section of the museum documents the children of S-21. Historical records note that out of thousands of victims, only 4 children managed to survive up until the final days of the prison; when the Vietnamese troops liberated the site on January 7, 1979, they were discovered hiding among a pile of victims’ clothes.

At the time of our visit there were still two of the survivors on-site, narrating their first-person accounts: Chum Mey and Bou Meng. Their lives were spared during their captivity because of their skills: while Bou Meng was a painter and he was tasked with producing Pol Pot’s portraits and other propaganda materials, Chum Mey was a mechanic and was kept alive because he could fix typewriters and sewing machines.

If you want to hear the voices of Bou Meng and Chun Mey, check out the documentary S21 The Khmer Rouge Killing Machine. It was shot in the S-21 prison, and it is a blood chilling recount of the events through the words of the former survivors, and the former guards.

Note for independent travelers: If you are not on a guided tour, make sure to pick up the audio guide at the entrance ($5.00 for non Cambodian languages), as it provides crucial narrative depth for every room and exhibit you walk through.

Essential Practical Tips for Your Visit

Recommended Order (Killing Fields First, S-21 Last): Plan your day to visit Choeung Ek (the Killing Fields) in the morning and finish at Tuol Sleng Genocide Museum (S-21) in the afternoon. This route naturally brings you back into the city center by the end of the day, making it much easier to process the heavy experience, grab a coffee or meal nearby, and head straight back to your hotel without an extra trip from the outskirts.

Getting There & Logistics: While an organized tour is the most seamless option, you can easily go independently by hiring a Grab tuk-tuk for a half-day return trip. Public city buses are available, but infrequent schedules make ride-hailing apps or private drivers a much more reliable choice.

Dress Code: Out of respect for the victims and the solemn nature of both sites, visitors should wear conservative clothing that covers both shoulders and knees.

Emotional Preparation & Etiquette: Give yourself plenty of mental space to process the heavy atmosphere. Maintain a quiet, respectful demeanor at all times, and pay close attention to signs regarding photography restrictions. Some sensitive areas inside the museum prohibit taking photos.

Conclusion: Is the Phnom Penh Killing Fields and S21 Prison Worth It?

Visiting the Choeung Ek Genocidal Center and the Tuol Sleng Genocide Museum is undeniably one of the most heartbreaking travel experiences you can undertake, but it is also one of the most vital.

While it is not a traditional sightseeing activity, confronting Cambodia’s tragic recent history firsthand offers a profound understanding of the country’s resilience and spirit today. It is an emotionally draining day, but bearing witness to these dark chapters ensures that the victims are never forgotten!

For a seamless experience, we recommend booking the same guided tour we took here.