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.

Most visitors to Fiumicino arrive by plane and immediately continue on to Rome, but—in addition to being home to Italy’s busiest airport—the coastal town doubles as a beach resort during the summer months. There’s also Ostia Antica archaeological site, which is just a short drive away.

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.

You've probably heard that Guinness tastes better in Dublin (fresh from the factory), but what you may not know is that Dublin is a perfect destination for the whole family. No, we're not suggesting you let the kiddies drink a pint. Instead, take them to the Dublin Zoo, to feed the ducks in Stephen's Green or on a picnic in Phoenix Park. Scholars enjoy walking in the literary footsteps of such writers as Yeats and Joyce, while discerning shoppers have their pick of designer boutiques.

The museums of Lisbon celebrate the rich history and culture of this Portuguese capital city. The Maritime Museum is perfect for kids (and grown-ups!) who adore all things nautical, while the Casa-Museu Dr. Anastácio Gonçalves is a hidden gem of colorful artwork. To fully appreciate the city’s dramatic stone architecture you can take a guided walking tour, or customize your own tour, making sure to visit the Padrao dos Descobrimentos, the Mosteiro dos Jeronimos, and the UNESCO World Heritage site the Torre de Belem.

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.

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.

Newark has been welcoming guests since its first hotel opened in 1670. From the largest number of cherry blossoms in the U.S. to one of the country's highest grossing arenas, from Shaquille O'Neal's supersized cinema to the biggest collection of Tibetan art outside Southeast Asia, it's all still happening in Newark. Just eight miles from New York City, Newark offers travelers quick access and easy connections. Jump in and discover pro sports, fine arts, urban retail and outdoor adventure.

One of the most historic cities in America, Philadelphia is an ideal place to spend a weekend - preferably a long one. Be sure to see the Liberty Bell and Independence Hall, where the Constitution and Declaration of Independence were signed. Both are part of Independence National Historic Park. Philadelphia also boasts some outstanding art museums, including the Rodin Museum. The Franklin Institute Science Museum is one of many area attractions honoring the life and work of Benjamin Franklin, the city's most famous ambassador. After digesting all of that history, be sure you save room for a classic Philly cheese steak sandwich.