Puerto Rico offers the perfect balance of rum-soaked nightlife and tranquil retreat. The Spanish colonial buildings of San Juan set a perfect backdrop for a day of shopping and sightseeing. Hike the massive El Yunque rainforest to see waterfalls, stone towers, and colorful Puerto Rican wildlife. As far as beaches go, it doesn’t get better than the private sands of Isla de Vieques – particularly Mosquito Bay, where by moonlight the water glows blue-green thanks to magical microorganisms.