Adults $21.95, children $12.95. under 3 is free. $2 cheaper if you buy online ahead of time. Parking is extra. If you plan on visiting multiple museums within a 9 day span, the city go pass is the beat deal.
You can also purchase tickets online and skip the line.
+1 We got the City Pass and were able to do the Big Bus tour (helpful to orient yourself on the first day), the Science and Industry museum, Fields museum, Willis/Sears tower and the Chicago Art Institute.. all for ~90$ -- quite the bargain!
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