Inbursa Aquarium (Acuario Inbursa) is at Av. Miguel de Cervantes Saavedra #386, across the street from the Soumaya Museum (M: Polanco, line 7). Bankrolled by Mexican billionaire Carlos Slim, this is not only Mexico City's first aquarium but is subterranean to boot; visitors enter at street level and descend four levels. There are five main tanks, artificially illuminated and inhabited by some 300 different species of marine life bred in captivity.
A “sunken ship” exhibit has a backdrop of anchors, a wooden mermaid and a fake whale skeleton. Other habitats replicate tropical reefs, shoreline ecosystems and the Amazon River basin, where piranhas, crocodiles, turtles and salamanders live in placid lagoons beneath a canopy of plastic jungle vegetation. There are also penguin and jellyfish exhibits and a walk-through tunnel with an acrylic glass wall that provides up-close views of sharks and manta rays.
Note: The aquarium is a popular destination for school groups, and as a result is often crowded. It also is located in the northern part of the city, away from the Historic Center; if you would rather not use the Metro subway system, arrange for taxi transportation from your hotel.