Number 10. Cape Florida State Park in Key Biscayne, Florida: "Cape Florida State Park, located at the south tip of Key Biscayne, provides clear, emerald-colored waters and gentle surf. This fine, white coral sand beach is great for swimming, as waves are knocked down by a large sand shoal offshore," says Dr. Beach. The Top 10 Beaches list is produced annually by coastal expert Stephen P. Leatherman, also known as "Dr. Beach," director of Florida International University's Laboratory for Coastal Research. (Lynne Sladky/AP Photo)