Photo: ajay_suresh, CC BY 2.0 Free museums & galleries in Chicago
Photo: ajay_suresh, CC BY 2.0 
Photo: Skvader, CC BY-SA 4.0 National Museum of Mexican Art
Free, always
Photo: Michael Barera, CC BY-SA 4.0 Smart Museum of Art
Free, always
Photo: The original uploader was Salsb at English Wikipedia., CC BY-SA 2.5 ISAC Museum
Pay what you wish
Photo: Chris Rycroft, CC BY 2.0