You Can't Go Wrong on the Timucuan
If you find yourself some day in the jungles of central Florida's Ocala National Forest, there's a little gem called Alexander Springs you should head straight for. 70 million gallons a day of crystal clear 72 degree water rise through the Earth and form an amazing pool that makes for prime swimming, snorkeling, and even SCUBA diving.
An entrance fee of $5.50 gets you into the recreation area, which includes bathrooms, ramadas, grills, concessions, and a campground, all within a short walk from the springs.
Around the pool itself the Timucuan Trail allows you to enter the otherwise almost impenetrable jungle, complete with boardwalk sections over the swamp and interpretive signs illustrating the plants and animals of the area. Named after the Timucuan Tribe that inhabited the area near the springs 1000 years ago, the trail winds through four separate natural environments (Aquatic, Swamp/Riverbottom, Oak Hammock, and Sand Pine Scrub) while poking it's head out twice on the spring pool itself via small docks. The ground can be muddy depending on rain, and the boardwalk sections have sunk and twisted on their pilings, so although it's a million times better than hacking through with a machete, it's not exactly wheelchair friendly.
Fishing from the docks is permitted, and there are also kayak rentals to add to the ways you can experience the area, just keep in mind that even though it's far from civilization, people come from all over the world to check it out. Weekends during the warmer months can pack the place, but we were the only ones in the springs on a Wednesday morning in April, and the water was perfect. Other than not allowing alcohol in the day use area, it might just be the perfect swimming hole. ( Of course there is always the campground! )
Check out the Triplog.