There are 2,000 years of history in Cologne, and visitors here will find everything from Roman towers to Gothic churches to fine examples of modern architecture. Cologne has a variety of museums, too—check out the Museum of Applied Art, the Museum Ludwig and, if you have a sweet tooth, the Chocolate Museum. Be forewarned, though—the gift shop at the latter will utterly ruin your diet.

Everyone who visits Paris for the first time probably has the same punchlist of major attractions to hit: The Louvre, Notre Dame, The Eiffel Tower, etc. Just make sure you leave some time to wander the city’s grand boulevards and eat in as many cafes, bistros and brasseries as possible. And don’t forget the shopping—whether your tastes run to Louis Vuitton or Les Puces (the flea market), you can find it here.

The Welsh capital may have begun its life as a Roman fort, but it's since become a bustling city. Where the fort once stood, Cardiff Castle has held court since the 11th century. It remains a central presence in the city, now full of lively art and music venues, hip boutiques, fun bars and modern hotels. Even with so many new and exciting things to see, the National History Museum is still the most visited attraction in Wales. Don't be the only visitor who plays hooky!

Laid out by British architect Edwin Lutyens, the Indian capital is a striking modern metropolis. A gracious contrast to Old Delhi's winding streets, the grand avenues and stately buildings of New Delhi are rich with history and culture, from Gandhi's Delhi home (and the site of his assassination) to the tomb of Humayun, a complex of Mughal buildings reminiscent of the Taj Mahal. Chaotic traffic is best left to the locals. Negotiate a good price for taxis or travel on the new Delhi Metro.

The Zanzibar Archipelago, located in the Indian Ocean 15 miles off the coast of Tanzania, is a breathtaking spot to escape from the world. You’ll enjoy clear, turquoise-blue water; shallow sandbars perfect for wading; and many small, nearly deserted islands virtually unvisited by tourists. Explore the World Heritage Site of Stone Town, Zanzibar City’s old quarter. Or just go beach to beach between tiny fishing villages—each one's better than the next.