Frederic and Joel covered the site pretty well, so I will try to add a few information from my side as the first reviewer after that visited the site after the inscription.

Important to mention is, that the Escuela Superior de Mecánica de la Armada (ESMA) is a pretty big and interesting campus, that includes five accessible buildings, many none accessible buildings that are still used today, old watch towers and also one of the planes that were used to drop dissident into Rio Plata. But only the Officers Quarters Building at the very corner of the campus is core zone. The rest is buffer zone. I highly recommend to visit the buffer zone as well, as it is very interesting and shows additional testimony of the victims. Our Uber dropped us off in front of the building, but unfortunately the entrance to the campus is almost at the other corner of Av. Del Libertador, which was a 400 meters walk not appreciated by my family.

Entry is free, but children (below 16) are not allowed to enter the inscribed building. Out of the four levels, only two could actually be visited. The officers quarters on level 2 and 3 were closed and I am not sure if it is planned to make them accessible (again). The relatively small number of accessible rooms makes this a relatively short visit. You can however spend lots of time in there watching all the testimony videos that are shown in the different rooms and read the info boards. It is also very unphotogenic on the inside. Basically small empty rooms with mostly info boards and video installations. There is nothing special about the building itself. This led to me not taking the usually way too many pictures of a WHS, despite the nice weather.

I totally agree with the other reviewers about the UOV. This is AOV (Argentinian Outstanding Value). It’s tragic, but I don’t see the worldwide impact. However, if you visit Argentina, chances are high you enter via Buenos Aires and this is a very easy tick as well as an good place to pick up some local history.

Joel's review of this excellent and disturbing museum is itself excellent (but fortunately not very disturbing!). He describes the site itself and its history exceedingly well, and I even share his opinion about the site's outstanding universal value. So I'll just add a few details about my visit.

I visited ESMA in March 2022, before its inscription on the World Heritage List. Like Joel, I was struck by the human side of the museum, with its emphasis on the testimonies of victims and survivors, the former far outnumbering the latter. The museum boasts 17 permanent exhibition halls, all recounting the events that took place there. The entrance portal is remarkable, with its windows covered with the portraits of those who died. A similar fresco can be found in the Escuela de Mecanica de la Armada (buffer zone).

The first room in which I took photos was the Capucha, on the third floor (banner picture above). This is where prisoners were held in cramped quarters. The description of the conditions of detention is bloodcurdling, particularly the details about the pregnant women held at ESMA whose children were handed over to members of the army who tortured the mother. This area also provides access to the Capuchita, the fourth-floor torture and solitary confinement room. The next room, the Pañol, describes the theft, fraud, and forgery committed by ESMA officers. They operated a well-honed machine of terror. Prisoners even worked on falsifying documents to further the propaganda of the totalitarian regime and the state terrorism of the Argentine government. Further on, we reach the Casa del Almirante, a large, modern, and well-decorated room that contrasts with the rest of the torture and detention center.

The basement is one of the most striking rooms in the building (picture above). This is where prisoners were tortured and interrogated. It was also the last place they visited before being murdered (often thrown out of a plane over the Río de la Plata). The basement also housed the equipment needed to produce the false documents required for the officers' propaganda (printing works, photographic laboratory, audio-visual studio), as well as an infirmary. It is here that a number of disturbing testimonies are recounted, and that torture and murder are made explicit. A low beam on which the heads of hooded prisoners were banged is clearly identified. And this is probably the most shocking of all. In fact, the prisoners were simply hooded as they moved between the third floor and the basement, in full view of everyone, including the cadets studying at ESMA. And no one said a word until bodies were found on the banks of the river in Uruguay.

This site is a powerful testimony to the atrocities committed by the Argentine dictatorship. It's one of the most interesting sites in Buenos Aires and an attraction not to be missed. But it's still not a universal WHS.

ESMA, the ESpacio MemoriA y Derechos Humanos (Human Rights and Memorial Space), belongs to a difficult category of Site. Like Auschwitz, Hiroshima, and the proposed sites of genocide memorial in Rwanda and WW1 memorials in Belgium/France, ESMA is dedicated to preserving the memory of a significant 20th century crime.

Located on the campus of the Naval Warfare School in leafy northern Buenos Aires, the main part of the museum is in the former Officer's Quarters, an imposing four-storey edifice in one corner of the campus. It's here that during the military dictatorship of 1976-1983, both political prisoners and innocent civilians were taken, tortured, beaten, confined to miniscule cells, and often, ultimately "transferred" (murdered, though the act was done elsewhere). Incredibly, while this was happening, the rest of the campus continued to operate as normal, with the majority of naval cadets unaware of what was taking place just a few hundred metres away. Almost literally hidden in plain sight.

As a child of the early 80s, and not particularly well versed in Argentine history, I didn't know much about the military dictatorship era other than "it existed". So the extremely well-organised and put together museum was genuinely eye-opening, and very harrowing. I was astounded to read accounts from survivors, and to discover that despite being confined to a blacked-out building, most captives were completely aware of where they were being held.

The busy six-lane boulevard Avenida del Libertador runs directly past with its ceaseless rumble of traffic, aircraft approaching and leaving Aeroparque Jorge Newbury pass overhead - they could even hear football matches (including Argentina's win at the 1978 World Cup Final!) being played at the massive River Plate stadium nearby. Again, it was literally hidden in plain sight. Overall, the museum is a harrowing but worthwhile experience, from the attic confinement spaces, to the torture areas of the basement, the relative luxury of the officers' areas, and the well-produced videos giving context behind the military coup and a "where-are-they-now" type coda (though as usual, it was depressing how little justice most of the perpetrators faced for crimes against their own people). I also really appreciated the strong focus on survivors' testimony, rather than just dry facts - it gave the whole experience much more emotional impact, and reduced me to tears multiple times.

However, I'm not so sure about the site's OUV. Outstanding? Definitely. Valuable? 100%. Universal? I'm not so sure. Naturally, the whole site is completely Argentina-specific, and I'm honestly uncertain whether something quite so modern and country-specific should be included on a "Universal" list. Given UNESCO's renewed focus on multi-national sites, it might be interesting to include similar locations from other South American countries, covering the similar issues of 20th century dictatorships in say Brazil and Chile, among others. Though I can imagine that would quickly become a diplomatic and political minefield!

Logistics

Getting to ESMA is easy. There's a bus stop directly out the front of the Naval Warfare School, with bus routes and timetables available on Google Maps and Moovit. Paying for public transport (both buses and subways) in BA requires an Oyster-style tap-on card; for buses you tell the driver where you're going, he'll punch the appropriate fare into his machine, and you then tap your card. Obtaining a card can be a pain, though most subway stations will sell them. Otherwise, Uber is available in BA though paying by card means you can't use the blue dollar exchange rate.