At 82 feet wide and 25 feet deep, this spectacularly beautiful natural spring bubbles up into a limestone basin next to the Withlacoochee River. Wooden steps lead down to a platform and a walkway leads to paddling and picnicking areas. This is also a prime destination for cave divers, with over 26,000 feet of passages exposed to date. In 2015 Madison Blue Spring was voted the country's #1 swimming hole; it's hard to imagine there being a better one.
If you go:
The park is open 365 days a year, from 8:00 am to sundown. Admission is $4-5 per vehicle (depending on size), and $2 for pedestrians, bicyclists and extra passengers.
Links:

8300 NE State Road 6
Lee, Florida 32059-7318 USA
Phone Numbers:
+1 (850) 971-5003