Dip your toes into the headwaters of Rock Springs Run, a true Floridian oasis amid Kelly Park's lush, green landscape and immediately the oppressive subtropical clime is replaced by goose bumps and a bit of a chill. Water courses into this natural spring from a crevice at the bottom at a brisk 68 degrees and if you're lucky enough to have the space to yourself and the sun is just right, you can see just about to the bottom. In places, the water here is an unearthly beautiful crystal blue. Kelly Park has camping and hiking and a swimming hole at the end of the creek's run, but the No. 1 activity here is a lazy, winding float trip �" about three-quarters of a mile and roughly 30 minutes if you don't stop �" to its culmination. Bring your own tube or rent one from a number of vendors outside the park.