Biscayne National Park Travel Guide. Imagine stepping into a tropical aquarium the size of a city. Biscayne National Park protects aquamarine waters, emerald islands, and fish-bejeweled coral reefs along the coast of southeast Florida. With 95 percent of its area underwater, the park preserves mangrove shorelines, shallow seagrass beds, and the northernmost Florida Reef, attracting snorkelers, boaters, and anglers to a watery world steeped in over 10,000 years of human histor