Since I had never been and neither had they my grandparents and I decided as part of their visit on their last day in town to make a trip over to the Atlanta History Center to check out what they had to offer. And actually they have quite a bit to offer.
The History Center is on a plot of land that consists of a nature trail, an historic farm, The Swan House and the History Museum itself and also includes the Margret Mitchell House (of Gone With the Wind fame) which is located at a separate location in Midtown, but you have 10 days to use your passes to visit.