La Rochelle's blockbuster crowd pleaser, this is one of the biggest aquariums in Europe. It rises from a portside position near the Port des Minimes, north of the old city. Inside are guided walkways stretching over two floors of massive and bubbling seawater tanks loaded with approximately 10,000 species of flora and fauna from the oceans of the world, living in what look like natural habitats. A new exhibit looks at the ecosystem of the Atlantic coastline. It's hard to miss this place; there are signs for it all over town.