As far as places that haven't been used; they haven't used Atlanta -- not even on TAR:FE. And as Peach can tell you there are some great places that can be used as a start or finish line, such as Centennial Olympic Park (you know how Bertram loves Olympic venues), Stone Mountain and its park (largest granite mountain east of the Mississippi River and largest urban park in the US), the Auburn Avenue Historic Site (Martin Luther King, Jr. and Ebenzer Baptist Church, the Georgia Aquarium (the world's largest), Zoo Atlanta (now regarded as one of the best zoological parks in the world), and others.
And Atlanta Hartsfield-Jackson International Airports has connections headed almost everywhere in the world (Africa, Asia, Europe, South America, and elsewhere in North America, and usually considered the world's busiest airport in number of passengers and flights.