We had some extra time during a recent trip to Minnesota for a Bible Quizzing competition to do a little exploring.
Como Park, Zoo & Conservatory. Free admision but they take donations & you have to reserve admission online. We didn't have time (& my son was anxious to get to the amusement park) so we didn't check out the Conservatory.
My son enjoyed the amusement park inside the Mall of America. It was nice I didn't have to pay to watch him ride the rides. The lines weren't too bad during the week when we were there.