Details from the Facebook Event page:
Carnegie Museums of Art and Natural History invite all of Pittsburgh to enjoy a fall afternoon at the museums, with five free-admission weekend days scheduled from August through November. In addition, the museums will be permanently expanding Sunday hours to 10 a.m.–5 p.m. beginning September 10. Currently, the museums open at noon on Sundays.
Admission to the two museums, which share a single admission charge, will be free on the third Sunday of the month—for four months—starting August 20. The Jack Buncher Foundation is sponsoring the first free Sunday on August 20, and UPMC Health Plan is the sponsor of free Sundays on September 17, October 15, and November 19.
In addition, the Oakland Carnegie Museums are joining the Allegheny Regional Asset District and organizations across the region to support this year’s RADical Days (September 22-October 15), with free admission scheduled for Saturday, September 23.
Standard parking and special activity fees apply.