Chicagoan beat me to it. We did the architecture boat tour last year and it was awesome. Perfect for a group.

Thanks! I will definitely look into the boat tour and drinks at the Hancock building. The restaurant recs are great too-this group likes classic fare.

Guidance from an attorney who has resided in Chicago (taking into consideration the group consists of adult lawyers and accountants):

Definitely the architectural boat ride tour (should be operating in Oct).

Drinks on the 95th floor in the Signature Lounge of the Hancock building.

The Chicago Cultural Center is across from the Art Institute and Millennium Park and it is a beautiful building. There are free tours provided.

Secure dinner at a steakhouse - David Burke Primehouse, Joe's Seafood, Prime Steak & Stone Crab, Gene & Georgetti (old school Chicago), etc.

I'd skip the Field Museum unless there is a special exhibit or event you are attending. The Field Museum is exciting for kids (see Sue the Dinosaur), but it's a disappointment when compared to the DC National Museum of Natural History.

I need to plan a group activity for around 20 people in the fall in Chicago. The group is all adults, ages 45-65, and they are all lawyers and accountants. Has anyone done any interesting tours or activities in Chicago that you would recommend? I have the obvious--Field Museum, Art Institute, CAF Architectural Tours, but wanted to see if anyone knew of anything a little different that might be right for this group. Since it is fall, I assume it will be pretty cold there, so we probably won't want to spend a ton of time outside. Walking is fine, though. Ideally the activity would be downtown, but if there is something really great we could get a bus to transport people.