St. Vincent National Wildlife Refuge at 3100 County Road 30A, Apalachicola, Florida.

What could go wrong on a three hour tour? Remember the SS Minnow?
You truly need a full day to walk the island, but the shuttle drops off at 9:30 and picks up at 12:30. Bring backpacks full of sun screen, bug spray and water for a true all day hike. Mosquitos are swarming and VERY hungry so spray down. You will be walking through a tropical jungle that reminds you of Jurassic park meets treasure island. It's very hot and humid, and the terrain is flat. But if the only exercise you get is walking in the mall, you're gonna have difficulties.
Don't forget that the time zone change is near this area, and depending where you are coming from, you might end up an hour late to catch the 5 minute shuttle ride across the bay.
This review is for the weekend tourist looking for a break from the beach ( oddly enough). Anyone who is really into nature, flaura and fauna, will probably love it.