Chiacgo attrctions

Cloud Gate
Skydeck Chicago
Observation deck
Riverwalk
Buckingham Fountain
Museum of Science and Industry, Chicago
Lincoln Park Zoo
Millennium Park

these are some places where you can enjoy yourself without any cost and can have fun in Chicago.

Say something about day trip from seattle.

Seriously??? Are you sure no cost is required to visit all of those places in Chicago, which you have mentioned in your post??

If it is true, then I just moved to Chicago with my family members. Because I can visit all of these places without any cost. Every traveler loves to spend in this kind of place which offers a low budget.

Yes, I am sure these attractions are free and spending time there with family members is a good option for travelers.

I must say don't waste your time in confirmation and just pack your bag to have fun there.