The largest Science Museum in a single building in the Western Hemisphere, Chicago's Museum of Science and Industry is a must-see for anyone visiting the city with children, especially after spending your other days in boring grown-up places like the The Art Institute of Chicago, or the Chicago Civic Opera.

Permanent exhibits include such cool stuff as:

1. A walk-through model of the human heart.
2. A complete coal mine set up inside the museum.
3. A real German Unterseeboot out in the Museum's back yard.
4. Various spacecraft, such as the Apollo 8 command module, a Lunar Module, and an exhibit on the current progress of the International Space Station.
5. A chick hatchery.
6. And for those of you who prefer to sit and stare at a screen, they've also got an IMAX theater.

They're online at www.msichicago.org. If you like it, you should also check out the John G. Shedd Aquarium and the Field Museum of Natural History while you're in the city.