Grand Cayman's splashier side is the real draw. Offering a host of experiences, from petting attention- and food-seeking stingrays at Stingray City to exploring jaw-dropping drop-offs and dive sites, Grand Cayman is a watery wonderland.

Glamorous Santorini, in the southern Aegean's Cyclades islands, curves round a giant lagoon, a caldera left by a volcanic eruption.

A beach-lover's paradise, this Caribbean island's interior boasts desert, but the coasts are filled with picture-perfect, powdery white sand and tranquil sapphire waters.

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.