The next time you spend a weekend in the Keys, make it your mission to find Mile Marker 37 and plan an entire day in the small piece of paradise known as Bahia Honda. With its emerald green waters caressing the powdery white sand, an effervescent coral reef just off the shoreline, and the tattered remains of the old Flagler Overseas Railroad in the backdrop, Bahia Honda State Park is one of the Florida Keys' best-kept secrets. It is, quite possibly, the best beach you'll find in all of Florida. The three beaches that make up Bahia Honda stretch out toward the Atlantic Ocean and the Gulf, and their waters are teeming with fish. Along with kicking back on the supple white sandy beaches — or in the shade of one of their many pavilions — and wading in the warm turquoise water, you can also take a hike along the Silver Palm Trail or ride along the bike path. The Bahia Honda Bridge is a great place for pictures or for spotting the nurse sharks that swim underneath the railroad. The park also features kayak rentals and boating excursions. Overnight lodging is available, but because reservations are tough to come by, it's probably best to stay at a hotel in Marathon, which is a good 20-minute drive away. Key West sits about an hour south. Park entry costs $3.50 per person, $6 for two (plus 50 cents for additional person), and $1.50 per walk-in. Open from 8 a.m. to sunset.