I've had the good fortune to see a lot of cool stuff around the state, but one of the most interesting things lately has to be Lime Sink Run at Suwannee River State Park in Live Oak. The Suwannee River by itself is incredible, but it's those side creeks and spring runs that really adds an extra level of awesomeness to the place.
Here's a panorama (don't mind the floating tripod head, okay?) of Lime Sink Run. Follow the flow on this particular section of the run, and you'll see that it only goes one place – underground. How cool is that? The other part of the run cascades out into the Suwannee River.
Spots like Lime Sink Run are why I love the Suwannee River. If you want a great basecamp to explore the area, reserve a spot at Suwannee River State Park. For more info, visit www.floridastateparks.org/suwanneeriver.