San Juan, Puerto Rico
The oldest city under the American flag, San Juan vibrates to a lively salsa beat. There's an unmistakable zest in the air here. Perhaps it's the stunning natural setting: the verdant peaks, tropical forests, and gleaming white-sand beaches. Or maybe it's Puerto Rico's mix of cultures, the blend and occasional clash of four centuries of Spanish heritage overlaid with a century spent as America's only Commonwealth. Whatever the reason, San Juan is one of the most enticing ports in the Caribbean, and it only gets lovelier with age.