Florida has always had an amazing blend of historical significance and fun. One of my favorite places as a kid was MarineLand. It was like Sea World, minus the crowds and fanfare. Sadly, I haven't been in years, and do not even know if the place is still open. If it is, I plan on getting out there, to relive some of the childhood fun.
Weeki Wachee is a kick ass historical waterpark in Spring Hill, Florida. I drove by there two weeks ago, while working, and the parking lot had maybe 15 cars in it. Sad, to see such a fun place so empty. Good news, as a tourist or resident, is that we have a pretty empty water park, an hour and a half from East Orlando (northwest, directionally), that you can take the family and enjoy without the crowds.
What other gems do we have in this area? Let's get away from I-drive and the Mouse. Let's get away from the crowds. Let's go have some fun in a place that's over-looked by most. Tell us about your experiences. Tell us why we should go. We should all try these places at least once, before the Mouse finally kills them off.