For an intense stay in the "real" Florida, consider one of the 47 backcountry campsites deep in Everglades National Park, many inland, with some on the beach. You'll have to carry your food, water, and supplies in; take care to carry out all your trash. You'll also need a site-specific permit, available on a first-come, first-served basis from the Flamingo or Gulf Coast Visitor Center. These sites cost $10 for a permit plus $2 per person per night, with a 14-night limit.