45 miles west of Americus, GA on Hwy 39C is what some have nicknamed Georgia's Little Grand Canyon - Providence Canyon State Park. You can hike to the bottom of the 150' gorge and there are primitive campsites available to be reserved on the park website. View larger map with driving directions.
The Jimmy Carter National Historic Site is in the nearby town of Plains, 10 miles west of Americus on US 280.
Why not skip the interstate?
Here's a 460 mile easy ride in south Georgia and north central Florida beginning and ending near Fanning Springs State Park. Located on the famous Suwanee River about 50 miles west of Gainesville, FL both I-75 and I-10 are near this route.
The western leg is all US Hwy 19, mostly 4 lane divided highway through rural countryside north to Americus, GA. The east leg is US Hwy 129, a 2 lane road. There's a lot of wide open spaces left in the rural parts of Florida, as you'll see on this ride. See larger map with directions.