Where else are Ernest Hemingway and Jimmy Buffett equally revered? Key West is a sunny, fun destination with enough sights to keep you busy when you're not snorkeling, parasailing or catching some rays.

Historic and modern, European and Asian — that's Istanbul. The city at the junction of two continents is home to ancient structures like the Hagia Sophia and the Blue Mosque in the Old City, as well as modern businesses, hotels, restaurants and nightlife in the New City.

"When in Rome, do as the Romans." That classic advice leads to a wealth of options: Should you follow Augustus and Caesar, whose Rome is filled with spectacular ancient structures? Or Michelangelo and Da Vinci, whose city invites artistic pilgrimage? Maybe you'll discover the Rome that enchants lovers and sightseers alike? Rome encompasses all this and more.

With its ultramodern skyline, it's easy to forget that Dubai, part of the United Arab Emirates, was once a small town of Bedouin traders.