Located in Union Station, the St. Louis Aquarium is a great attraction to take your family during your stay in STL! You can visit the website to purchase tickets ahead of time.
Union Station also has a Ferris wheel that is climate-controlled year-round! There are options to purchase wheel + aquarium combination tickets, or wheel only tickets.
The zoo is free!!! And so much fun for everyone.
The City Museum is an indoor / outdoor interactive museum for people of all ages. With slides, tunnels, art exhibits, a rooftop, and more, it would be a great afternoon with your family!