Coming to Chicago

It’s quite last minute, actually as of yesterday, I am coming to Chicago next week for the Climate Reality Leadership Corps training. I’m not really sure that I will have any free time, but if I do, where should I go and what should I do? What are the iconic and the off-beaten things that everyone must do/visit when they go to Chicago? I’ve never been before and I really would like to do at least one thing outside the hotel and outside the conference. Tell me about it, Chicago. What can’t I miss?
Photo: Conway Yao