Cloudland Canyon is our local gem. Only a two hour drive from Atlanta and often available for camping with little or no notice except during peak times of the year. My family including my daughter at only 4 yrs of age hiked the majority of the trails this day without complaint (my daughter is amazing). The view from the rim is spectacular. The waterfalls at the bottom are well worth the short hikes.
I understand there is some good caving in the area and next time I intend to check take my daughter and do some belly crawling in the mud. There is apparently a female run adventure tourism group that takes people into these caves but you must call ahead and make a reservation a day or more in advance.
I have to say that it is places like Cloudland that inspire my designs. I love to study the rock formations and how the boulders are strewn along the creeks and distributed in the channels. I use this understanding when creating water features of my own. There is not much I like less than a man made water feature that looks like a truck simply dumped some rocks along a channel. In nature the larger boulders are usually half buried along the edges and smaller boulders stack up behind the larger ones where the fast water can not move them. Larger boulders also occur in the bends and deposits of sands and smaller pebbles occur behind them.