Excellent choice! City Museum is a great place for kids and adults alike. There is nothing like it any place in the world. It's a marriage of mad genius and salvaged historic architecture of St. Louis.
It was built by Bob Cassilly, my neighbor, who was a maniac. He died the way he would have wanted to die, on his bulldozer (it turned over on him.) Throughout my neighborhood are archietectural replicas, near follies, designed by Bob.