It seems to be quite a common thing, for people to say they "never" see tuatara in overseas zoos. I find it interesting because I don't think I've ever had trouble seeing them in NZ collections.
I have visited Chester during every single month and season, and to the best of my recollection the only month I have never successfully seen a tuatara is January. They are a little less showy in the winter as a whole, but still visible, whilst during the rest of the year they are pretty damn easy to spot!
As @Maguari says, the ones at Zoo Berlin are a lot less showy,
Of the four zoos that have tuataras in the US, I've been to three. Other than San Diego, which always keeps theirs off-exhibit, I have had pretty good success when it comes to seeing the species. I only missed the species at Dallas once, and always saw the species at Saint Louis when it was on exhibit. A friend who visited Toledo saw theirs easily as well. Of the zoos that exhibit the species (or when they are exhibited, in the case of Saint Louis), all the exhibits are inside. I only hear complaints of not being able to find the species from European zoos.
@Chlidonias@Maguari I don't know why everybody always complains about not seeing them, on five visits I have always seen them and often more than one... Maybe these Kiwis just do not like Englishmen
I recall on my own visit in 2022, that I initially only saw at the entrace to one of the burrows one of the tuatara's tails, but, after persisting around the tank for some amount of time, the animal turned around to reveal its face! Tuatara - Berlin Aquarium 2022 - ZooChat
I had seen the species before at Chester, but here I was able to get some better shots!