The Missouri Historical Society operates the Missouri History Museum in Forest Park in the heart of St. Louis. Admission to the museum is FREE! This is a wonderful museum, especially for those that grew up living or visiting St. Louis. It is housed in a beautiful building, the exhibits are very interesting. Currently there is an ongoing exhibit from the 1904 St. Louis World's Fair which I found very interesting because some of the buildings are still standing in Forest Park. There is generally a traveling exhibit that does charge an extra fee (currently Ben Franklin) but you can have a great time without spending any money. http://www.mohistory.org/content/HomePage/homepage.aspx
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