An aquarium is a place that stores fishes and other sea life for others to see in tanks. They're popular places that you can take friends and family. [ffff he's finding that really cute, but he'll be keeping that comment to himself.]

... Cloche-san. It would next to impossible to show you the entire ocean since it makes more three-fourths of the Earth! You would have to get on an airplane and fly around the world if you wanna see it all!