Bioluminescent Bay, Vieques, Puerto Rico
Location: 55 miles southwest of San Juan

Just off the eastern shore of Puerto Rico sits the island of Vieques, home to hundreds of unspoiled beaches. The real draw is the fluorescent light show in the bioluminescent bay. Millions of microscopic algae flash neon blue-green when disturbed, surrounding swimmers and boats in a halo of light. Make sure to visit on a moonless or cloudy night.