At over 200,000 acres, Tate's Hell is the second largest State Forest in Florida, second only to Blackwater River State Forest in Santa Rose County. That's Hell is located off of U>S> Highway 98 in Franklin County, between the Apalachicola and Ochlockonee rivers. Check out The Ledgend of Tate's Hell on the State Forest webpage, https://www.fdacs.gov/Forest-Wildfire/Our-Forests/State-Forests/Tate-s-Hell-State-Forest.
For roughing it in the woods, nothing I have found beats Tate's Hell. With 36 primitive campgrounds (tent space, fire ring, and picnic table) with multiple campsites and 4 campgrounds with facilities (restrooms and some RV sites) there is plenty of room to camp and explore Tate's Hell.
The Womack Creek campground, where I spent one night, has both RV and tent campsites and a boat ramp with access to Womack Creek.
Recreation opportunities include the High Bluff Coastal Hiking Trail which is part of the Forest Service's Trailwalker Program.