While in Paris, just a few minutes from the Eiffel tower, there is now an aquarium. Actually it's been around for 10 years now, but honestly I had never heard of it. It's been dug into the ground where there was nothing before, so honestly I didn't expect much, and to be honest it wasn't much, but eh, it's still an aquarium, worth about 1h or so.
The highlight was actually the touch pool at the end with big carps that were happy to come brush towards your hands, I even had several that tasted my hand with their mouth. Funny how curious they were, maybe they were hoping for food.
and the carps at the end (no, they weren't magikarp, but they were friendly :)