JMSAZ

As a kid, this was the museum we would duck into quickly if we finished at the Field and Shedd early. There was never much to see during the day, but we could find out our weight on the moon. At some point in the last 20 years they dramatically expanded and improved the exhibition halls, and now it is a fascinating museum. Much like the Shedd, the architecture is fascinating, and the Adler has the world's largest collection of historical astronomical instruments in the world. The front steps also provide the best view of the Chicago Skyline you can get on dry land.

http://www.adlerplanetarium.org/