Frank Lloyd Wright

There are many Wright designed and built houses in the Chicago area. His own Home and Studio the famous Robie House and Unity Temple. Also, the Bach house, the Rookery. There are 10 other Wright design houses that are viewable from the exterior only, as they are private residences.
Tours are arranged by the Frank Lloyd Wright Trust. The best tour may be the Wright Around Oak Park tour that goes to his House and Studio, Unity Temple plus 10 other Wright homes in Oak Park! Those 10 are exterior only - presumably private residences. Walking tour with a limit of 10 people. It is about 3 hours long and costs $60.
There is also a biking tour available (bicycle provided) called Pedal Oak Park that visits 21 Wright-designed structures. It is about 2 hours long and costs $45.

Probably the best place to stay while on a tour is the Lang House and the Emil Bach House which are renovated FLW designed homes. Booking is available through their website.

Walking Tours

A favorite on TripAdvisor is Chicago Detours who offer a variety of walks: architectural exterior, architectural interior, food, music, gangster, etc.

Chicago 360 Observation Deck

Get a bird's eye view of Chicago from 1500 feet above. 360 Chicago.

U-Boat

A German U-Boat captured during World War II is on display at the Museum of Science+Industry. The optional tour inside the vessel is only $18.00. A must see. Museum of Science+Industry.