Biscayne National Park (Dante Fascell Visitor Center)

Ninety-five percent of this national park is water, so the mainland visitor center at Convoy Point is the only part you can reach by car. Free admission, a small museum on the reef and mangrove ecosystems, a breezy jetty walk, and the launch point for concession boat trips out to Boca Chita Key's lighthouse, Elliott Key and the snorkel reefs.

Without a boat booking it is a pleasant hour with skyline views across the bay. With one, it becomes a full day on the northernmost living coral reef in the continental US. Bring serious bug spray.