On Friday, July 11, 2025, during its 47th session held in Paris, France, the World Heritage Committee unanimously approved the inscription of “Memorial Sites of Cambodia: Former Security Prison M-13, Tuol Sleng Genocide Museum, and Choeung Ek Genocide Center, From Sites of Crime to Centers of Healing and Peace” on the UNESCO World Heritage List. This decision, made at the request of the Royal Government of Cambodia, marks an important milestone in preserving the memory of the Khmer Rouge regime, which led to the deaths of more than 1.7 million Cambodians. The recognition reinforces a global commitment to remembering this dark chapter in human history and ensuring that its lessons are shared both in Cambodia and internationally.

For decades, the Tuol Sleng Genocide Museum has stood as a powerful symbol and historical reminder of the systematic torture, forced interrogations, and executions carried out during the Democratic Kampuchea regime. Similarly, the Choeung Ek Genocide Center has also served as a symbolic memorial to the countless Cambodians who perished under Khmer Rouge rule. In contrast, the former security prison M-13, initially a Khmer Rouge crime site, has remained largely overlooked by the public until now.

According to the Documentation Center of Cambodia’s Khmer Rouge Crime Site Research Project, the former Security Prison M-13, located in Tomneab Village, Am Laeng Commune, Thpong District, Kampong Speu Province^[1], was established by the Khmer Rouge resistance movement as a facility to interrogate, torture, and execute individuals accused of being affiliated with areas controlled by the Lon Nol regime. Kaing Guek Eav, also known by his alias Duch, served as the director of the facility. He was later sentenced to life imprisonment by the Extraordinary Chambers in the Courts of Cambodia (ECCC), commonly known as the Khmer Rouge Tribunal, and died in 2020. In his testimony before the ECCC, Duch stated that killing was the main policy at M-13 Prison and that his mission there was to protect the people in the liberated areas. He also claimed that the prison operated to serve the broader objectives of the Khmer Rouge revolution^[2]. Ham In, a former guard at the prison, testified that approximately 30,000 people died at M-13 Prison due to executions, disease, and flooding. He emphasized that Duch held sole responsibility, as his orders were absolute and unquestioned. M-13 prison was overseen by five key individuals: Duch as president, Chan as vice president, and Pon, Phal, and Meas as members. These five were described as the “prosperous” of the revolution, among the most trusted cadres of Angkar.^[3]

The guards at M-13 Prison were recruited by the Khmer Rouge resistance movement, primarily selecting children under the age of 15. Duch personally recruited several guards, including Sim Vun (alias Din), Chan Voeun, and Chan Khon. The management of M-13 Prison was highly secure, surrounded by a fence made of bamboo and natural wood, standing five to six meters tall. The facility included more than four houses for the leadership’s residence, an interrogation room, and a separate room for the guards. Initially, most prisoners were soldiers and local civilians who did not conform to the party’s ideology. Several pits, each approximately four square meters in area and five to six meters deep with a central pole, were dug for detaining and torturing prisoners. Those who failed to provide the desired answers were subjected to severe torture, often resulting in death. The tools used for interrogation included pins, chains, hammers, rulers, and whips. Torture methods ranged from binding prisoners’ hands to poles, suspending their feet off the ground, driving needles into fingernails, stabbing with knives, beating the chest and back with wooden hammers, to forcibly pouring soapy water into the stomach through a hose. Duch was noted as the most brutal interrogator and torturer at the facility.

The surviving prisoners from the massacre, along with new detainees, were forced to work daily in chains and shackles under the strict supervision of the guards, who were authorized to shoot anyone attempting to escape. Many prisoners succumbed to exhaustion and malnutrition due to inadequate food supplies. Their forced labor included building dams, planting potatoes, clearing forests, and preparing land for rice cultivation. The prisoners’ diet was entirely controlled by the cadre management responsible for the kitchen. Each prisoner received only a small bamboo tube filled with liquid porridge per meal. In contrast, the guards’ rations consisted of a bowl of rice mixed with cassava and corn, while higher-ranking officials were allotted sufficient portions of rice to sustain them.

The recent official recognition by UNESCO holds profound significance for Cambodia. It marks the country’s first inscription of “modern and non-ancient archaeological sites” and is among the earliest globally to recognize sites associated with contemporary conflict. UNESCO’s acknowledgment expands the World Heritage List beyond ancient temples and natural wonders to include places that bear witness to profound human tragedy and resilience. In a message following the inscription, Samdech Thipadei Hun Manet, Prime Minister of the Kingdom of Cambodia, emphasized that “Cambodia’s Memorial Sites, including the Former Security Prison M-13, the Tuol Sleng Genocide Museum, and the Choeung Ek Genocide Center, From Sites of Crime to Centers of Healing and Peace”  now inscribed on the UNESCO World Heritage List, represent Cambodia’s greatest gift to humanity as hese sites stand as powerful symbols of remembrance, national reconciliation, justice for victims, education, and the ongoing efforts to build and safeguard peace.

Mr. Chhang Youk, Executive Director of the Documentation Center of Cambodia, acknowledged that Cambodia “still struggles with the painful legacy of genocide, torture, and mass atrocities.” However, he emphasized that the inclusion of the three sites on the UNESCO World Heritage List will play a vital role in educating Cambodia’s future generations, as well as people worldwide. He added, “Although these sites are places where violence occurred, they also hold the potential to help heal the wounds of the past that remain unhealed.”

Translated by: Lim Iphing

^[1] Searching for the Truth Magazine, No. 22, October 2001, Duch’s M-13 Prison, Documentation Center of Cambodia, page 22

^[2] Monitoring Report of the Khmer Rouge Tribunal (April 6-9, 2009) Link to Microsoft Word – monitoring Report on Duch Trial W2, 06-09 Apr 09, Final kh.doc

^[3] Pheng Pongsarasy, Special Regional Security System M-13, Documentation Center of Cambodia