Thanks to Covid-19 and visiting on a week day in September I probably had my only chance of ever taking pictures of visitor areas in the aquarium, such as this tunnel, without people in them. During my 2019 visit this tunnel was packed with people.
@Mr Gharial Of the top of my head I couldn't come up with any other example of a square tunnel I've seen. All the other aquarium tunnels I have seen always had a rounded top. Some research on ZooChat and Google images also didn't turn up any square tunnels like this one. That said, this is a fairly short tunnel and it was built when Pairi Daiza was still Parc Paradisio and a very different place to what it is now, so maybe that has something to do with it. Side note: there is another tank that is basically a square tunnel tank, sitting over a restroom, elsewhere in the aquarium building.
In a tank with Elasmobranchs that is probably also more appropriate, given the sensitive nature of their receptor-rich snouts.
Also, this tank is on the small side for several of its inhabitants, especially for the large loggerhead and the larger sharks housed here. Unfortunately it isn't the only tank in Pairi Daiza that has that issue.
To me the aquarium is one of the more outdated and disappointing parts of Pairi Daiza.
@Mr Gharial That in my opinion is one of the major downsides of Pairi Daiza and also one of my biggest criticisms: that in too many cases the theming is excessive and comes at the cost of exhibit quality, as well as distracting from the animals.