This interactive children’s museum offers interactive art meant for kids. Installations are designed by artists, so tykes can learn principles of movement and physics while simultaneously being exposed to art and working out the ants in their pants. Exhibits change every 18 months or so, so there's always something new.
If you need to get the kids outdoors, there's a futuristic playground across the street, and for a more traditional children's museum (with science exhibits and such), visit the Reuben H Fleet Science Center.