35 miles S of Miami; 21 miles E of Everglades National Park

With only about 700,000 visitors each year (mostly boaters and divers), the unusual Biscayne National Park is one of the least-crowded parks in the country. Perhaps that's because the park is a little more difficult than most to access -- more than 95% of its 181,500 acres is underwater.

The park's significance was first formally acknowledged in 1968 when, in an unprecedented move (and despite intense pressure from developers), President Lyndon B. Johnson signed a bill to conserve the barrier islands off South Florida's east coast as a national monument -- a protected status just a rung below national park. After being twice enlarged, once in 1974 and again in 1980, the waters and land surrounding the northernmost coral reef in North America became a full-fledged national park -- the largest of its kind in the country.

To be fully appreciated, Biscayne National Park should be thought of as more preserve than destination. Use your time here to explore underwater life, but also to relax. The park's small mainland mangrove shoreline and keys are best explored by boat. Its extensive reef system is renowned by divers and snorkelers worldwide.

The park consists of 42 islands, but only a few are open to visitors. The most popular is Elliott Key, a former community of pioneers, pineapple farmers, sponge farmers and wreckers, which has campsites and a visitor center, plus freshwater showers (cold water only), restrooms, trails, and a buoyed swim area. It’s about 9 miles from The Dante Fascell Visitor Center, the park’s official headquarters on land. During Columbus Day weekend, there is a very popular regatta for which a lively crowd of partiers gathers—sometimes in the nude—to celebrate the long weekend. The 29-acre island known as Boca Chita Key, once an exclusive haven for yachters, has become a popular spot for all manner of boaters. Visitors can camp and tour the island’s restored historic buildings, including the county’s second-largest lighthouse and a tiny chapel.