I want to recommend Torreya SP, about an hour west of Tallahassee, to other flatland hikers looking for a terrific place to train for your upcoming AT hike. The terrain is the most challenging I've found and combined with the condition of the trails, and the other park facilities it's the best place I've found in Florida to prepare for my, all too fast approaching, AT hike.

I learned about it a few years ago when my daughter was a student at FSU. They have some pretty intense adventure events there that she competed in. Torreya SP is located at the tail end of the Appalachian mountain range and offers, by far, the best terrain in the state. The park itself is a hidden gem. Besides having a very nice conventional campground there are primitive sites on the two challenging loop trails perfect for an effective shakedown hike.

It's a little bit of a drive for folks in the population centers of Florida but it's worth the trip. My pal Lefty and I are headed there next Monday March 3 so I can get in my second to last shakedown hike before my April 3 step off date. We are going to spend two days on the trail. If you have never been to Torreya I encourage you to check it out. If you want to join us on the trail we'd love to see you.
https://www.youtube.com/watch?v=hyYO3VyaiCE