The St Louis Science Center is a great place to visit, and admission and parking is free! There are tons of things to see and displays to interact with, as well as lot of seating for tired-out parents!
Occasionally, the dome will dress up for the holidays, so keep an eye open when you pass it 64-40.
One warning though, their opening hours change, depending on the season or break, so it would be a good idea to check or call ahead to be sure.
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