Mentioned by Busy Tourist
51 Best & Fun Things To Do In Chicago (Illinois)
"With more than 35,000 creatures, the Shedd Aquarium is one of the largest aquariums in Illinois. Not only does it house all of the sharks and stingrays that you’d expect, but it also showcases birds, bugs, snakes, amphibians and other creatures related to the sea. The exhibitions are mostly divided by theme."