Rome wasn't built in a day--and you'll need much more than a day to take in this timeless city. The city is a real-life collage of piazzas, open-air markets, and astonishing historic sites. Toss a coin into the Trevi Fountain, contemplate the Colosseum and the Pantheon, and sample a perfect espresso or gelato before spending an afternoon shopping at the Campo de’Fiori or Via Veneto. Enjoy some of the most memorable meals of your life here, too, from fresh pasta to succulent fried artichokes or a tender oxtail stew.

Once known for smog, traffic and tacky architecture, Athens is a city reformed thanks to fortunes brought by the 2004 Summer Olympics. Spotless parks and streets, an ultra-modern subway, new freeways, an accessible airport and all signs in perfect English make the city easily negotiable. Meriting more than a stopover en route to the islands, sophisticated Athens sites include many pillars of Western history, from the Acropolis to the Temple of Olympian Zeus, as well as treasures in the National Archaeological Museum.

Nicknamed the "Santorini of Spain," Altea draws laid-back travelers to the Costa Blanca with its hilltop old town and pebble beaches. Navy-domed landmarks and whitewashed walls stand out against Mediterranean skies, while three marinas provide plenty of offshore opportunities.

Lingering over pain au chocolat in a sidewalk café, relaxing after a day of strolling along the Seine and marveling at icons like the Eiffel Tower and the Arc de Triomphe… the perfect Paris experience combines leisure and liveliness with enough time to savor both an exquisite meal and exhibits at the Louvre. Awaken your spirit at Notre Dame, bargain hunt at the Marché aux Puces de Montreuil or for goodies at the Marché Biologique Raspail, then cap it all off with a risqué show at the Moulin Rouge.

From Shoreditch’s swaggering style to Camden’s punky vibe and chic Portobello Road, London is many worlds in one. The city’s energy means that no two days are the same. Explore royal or historic sites, tick off landmarks from your bucket list, eat and drink in exclusive Michelin-starred restaurants, enjoy a pint in a traditional pub, or get lost down winding cobbled streets and see what you stumble across – when it comes to London, the possibilities are endless.

Walk the Freedom Trail the first time you visit Boston and you'll quickly get a sense of this coastal city's revolutionary spirit and history. But make sure you also explore some of Boston's fine museums (try the Isabella Stewart Gardner, featuring masterpieces displayed in their collector's mansion) and old neighborhoods (like the North End, Boston's Little Italy). You can't claim to have experienced real Boston culture, though, until you've watched a Red Sox game from the bleachers.

Montreal, c’est si bon! This French-speaking city is considered the cultural capital of Canada, and is a cosmopolitan celebration of Québécois style. A horse-drawn carriage ride around the cobblestone streets and grand buildings of Vieux-Montréal will give you a taste of European flavor. The Basilique Notre-Dame is a confection of stained glass, and the Plateau Mont-Royal district will delight you with its quaint boutiques and cafés. Dig in to a massive plate of poutine to fuel up for a tour of the epic Olympic Park.

Conquering New York in one visit is impossible. Instead, hit the must-sees – the Empire State Building, the Statue of Liberty, Central Park, the Metropolitan Museum of Art – and then explore off the beaten path with visits to The Cloisters or one of the city’s libraries. Indulge in the bohemian shops of the West Village or the fine dining of the Upper West Side. The bustling marketplace inside of Grand Central Station gives you a literal taste of the best the city has to offer.