Outstanding Atrocity Sites

[Maria Elander is an associate professor at La Trobe University Law School.

Rachel Hughes is an associate professor at the University of Melbourne.]

In what way can a property that was once the site of an atrocity and now of memorialisation be outstanding? An outstanding book might be exceptionally good, an outstanding performance suggests one that stands out from the rest, while an outstanding bill is one that remains unsettled or due. In what sense can an atrocity site be outstanding?

Two weeks ago on 11 July 2025, the World Heritage Committee inscribed Cambodian Memorial Sites: From centres of repression to places of peace and reflection to the UNESCO World Heritage List. The Cambodian Memorial Sites include former Khmer Rouge security centre S-21, now Tuol Sleng Genocide Museum, the associated execution site Choeung Ek Killing Fields, and the lesser-known precursor security centre to S-21, M-13. 

The decision and the listing stand out: Of the 950+ properties listed as cultural heritage on the World Heritage list that now includes the Cambodian Memorial Sites there are only eight properties, comprising less than 2% of the list, associated with recent conflicts and ‘negative’ memory. 

The inscription of Cambodian Memorial Sites is a recognition of their outstanding universal value.  ‘Outstanding’ is a key operating term in the definition of ‘cultural heritage’ in the 1972 Convention Concerning the Protection of the World Cultural and Natural Heritage (‘the World Heritage Convention’). For a monument, group of buildings or site to be inscribed as cultural heritage on the World Heritage List, it must, other things considered, be ‘of outstanding universal value’ (OUV; Article 1 World Heritage Convention). Within the Operational Guidelines for the Implementation of the World Heritage Convention (‘the Operational Guidelines’), the meaning of ‘outstanding’ is very clear: For the purposes of the Convention, outstanding cultural heritage ‘is so exceptional as to transcend national boundaries and to be of common importance for present and future generations of all humanity’ (Art 49). Outstanding, as set out here, means exceptional and important.

But there are more ways to read it. In the following, we will suggest a reading of ‘outstanding’ that is against the grain. In contrast to a reading that seeks to identify or capture the ‘spirit of the text’, we provide an alternative reading to provoke fruitful discussion of the relationship between crimes, memory and world heritage recognition. 

What is Cultural Heritage for the Purposes of UNESCO?

Heritage is an interpreted product of the past, a mnemonic that connects us with the past and the future. Within heritage studies, scholars have long discussed ways of approaching, understanding and working with heritage that is associated with violence, war or other kinds of ‘negative’ or traumatic pasts. The attention stems from a fundamental tension in understandings and definitions of heritage, whereby heritage is usually conceived of as something ‘positive’ that can be ‘celebrated’. Yet, a war memorial, a genocide museum, or a building used to detain people might be significant for social, cultural or political purposes, but cannot be ‘celebrated’. 

Instead, heritage scholars use terms such as ‘negative heritage’ to capture a ‘conflictual site that becomes the repository of negative memory in the collective imaginary,’ ‘dark heritage’ for sites associated with pain and death, and ‘dissonant heritage’ for heritage that jars, is in an uneasy tension or remains unsettled.

The central international treaty for heritage is the 1972 Convention Concerning the Protection of the World Cultural and Natural Heritage (‘the World Heritage Convention’ or ‘the Convention’), which, as noted above, provides definitions of heritage for the purposes of World Heritage listing. In order for a property to be considered to have Outstanding Universal Value, it must meet at least one of ten criteria specific criteria, the most relevant for atrocity sites being criterion (vi), to: ‘be directly or tangibly associated with events or living traditions, with ideas, or with beliefs, with artistic and literary works of outstanding universal significance’. 

The Convention does not explicitly include or exclude ‘negative’ heritage. Before 2023, there were only three such sites associated with recent conflicts listed as World Heritage: The Auschwitz Concentration Camp, the Hiroshima Peace Memorial (Genbaku Dome), and Robben Island, which had been listed in 1999 as a ‘symbol of triumph of the human spirit, of freedom and of democracy over oppression’. But after receiving a number of nominations of such properties in the late 2010s, the World Heritage Committee decided to put a moratorium on their assessment to review whether and how properties associated with recent conflicts might meet the criteria of cultural heritage. 

The list of concerns over inscribing atrocity sites is long and has raised significant debate amongst and within the World Heritage Committee, the International Council on Monuments and Sites (ICOMOS, the leading non-governmental organisation operating as advisory body to the World Heritage Committee), heritage professionals and academics. Sites associated with recent conflicts can be divisive and heritage listing risks reinforcing divisions in society with one-sided memorialisation practices. Inscription might conserve or freeze a particular memory and, perhaps more fundamentally, risks contradicting the objectives of UNESCO and its spirit of peace. 

Despite deeply differing views presented during the review, the Committee decided in 2023 to no longer preclude evaluation of such sites for inscription. Shortly thereafter, three such properties were listed: ESMA Museum and Site of Memory – Former Clandestine Centre of Detention, Torture and Extermination in Argentina; Memorial Sites of the Genocide: Nyamata, Murambi, Gisozi and Bisesero in Rwanda; and Funerary and Memory Sites of the First World War (Western Front) in Belgium and France). The Nelson Mandela Legacy Sites in South Africa were listed in 2024, and now in 2025, the Cambodian Memorial Sites.  

Cambodian Memorial Sites

The Cambodian Memorial Sites, like the Rwandan Memorials Sites, is a serial property with three interconnected sites. Two of these are well known: The Tuol Sleng Genocide Museum stands on the site of former security centre S-21, which during the Khmer Rouge regime operated under the leadership of Kaing Guek Eav, alias Duch, as a site of detention, investigation, torture, and conviction. Most of the near 18,000 prisoners who entered S-21 were later killed at the nearby Choeung Ek Killing Field, the second of the three sites that make up the inscribed property.

Immediately after the Khmer Rouge were forced out of Phnom Penh, S-21 was turned into a memorial museum with the name Tuol Sleng. In its early days, thanks to the meticulous documentation under the auspices of Duch, it operated as an archive of information to which many Cambodians turned in search of loved ones. During the first years, it was also a place where foreigners were taken to learn and bear witness to the genocide. 

Choeung Ek was discovered soon after villagers returned to the area and was in 1981 turned into to a Genocidal Center responsible for the care of the mass graves and the visiting public. 

The third site of the inscribed property is that of former prison M-13, a precursor to S-21, which was operational between 1973 and 1975 under the leadership of Duch. The location of M-13 was for a long time unknown, but in 2015 it was located by historian Hang Nisay. Hang, the current Director of Tuol Sleng Genocide Museum, completed a surface search for physical artefacts in 2019, interviews with local informants in 2019 and 2020, and site excavations in 2023. After further archaeological examination, including by Ground Penetrating Radar, the site will be prepared as a memorial site.

The three sites together bear witness to violence that has been found by the Extraordinary Chambers in the Courts of Cambodia to have constituted war crimes and crimes against humanity. As the World Heritage Committee states in its decision to inscribe the three properties, ‘the scale and impact of the events [of the Khmer Rouge repressive system of imprisonment, interrogation, torture and execution] and the impacts on the people of Cambodia are of outstanding universal significance.’ 

Outstanding Memorial Sites

A major concern with inscribing atrocity sites to the World Heritage List is their potentially divisive nature. When the nomination of Hiroshima Peace Memorial was discussed, China pointed to the irony of a Japanese site being inscribed given that ‘it was the other Asian countries and peoples who suffered the greatest loss in life and property’. The US disassociated itself from the inscription, concerned by ‘the lack of historical perspective in the nomination’. 

Both statements reflect a concern with one-sided accounts or memories of violence. Memorial interpretation and practices are never – and ought not to be – stagnant or frozen. But perhaps inscription does not require the freezing of memory? Auschwitz, as Jonathan Webber points out, has constantly changed and evolved since its 1979 inscription in terms of the ‘lessons’ it teaches. Since Tuol Sleng began operating as a memorial museum in 1979, and Choeung Ek in 1981, they have continued to evolve and change. Researchers continue to uncover new materials from the regime – from new forensic examinations of the bones at Choeung Ek, to graffiti on the walls at S-21/Tuol Sleng, to archaeological findings at M-13 – which drives research that advances understandings of the reasons for and the mechanics of an atrocity. Similarly, as memorial museums have operated for more than 40 years, practices of memorialisation have continued to change. In the Cambodian case, and as evidenced by Tuol Sleng’s visitor books from the early days, its creation and then dismantling of the so-called ‘map of skulls’ exhibit, and the erection of a new memorial stupa at Tuol Sleng that came out of the hybrid tribunal process, memorialisation practices change. 

On this basis, we urge consideration of the Cambodian Memorial Sites – as for other atrocity sites that are memorialised – as outstanding in the sense of unresolved. It is not yet resolved how to best honour those who were killed, how to most appropriately represent the violence so that visitors, whether school children or tourists, learn well what occurred, or how to ensure that it never again occurs. Memorialising is iterative, in part because atrocities and their memorialisation are inherently dissonant as it is not the violence or its causes that is ‘celebrated’ but rather the negative effects and impacts that are commemorated. The Cambodian Memorial Sites may well be outstanding, as the World Heritage Committee has just found, notable in the exceptional scale and impact of the violence they exemplify. But the memorialisation of such exceptional violence can only ever remain unresolved.  

Photo attribution: “Buddhist Stupa at Choeung Ek killing fields, Cambodia” by Timgray200 is licensed under CC BY-SA 3.0