Over the centuries, many cultures have added their mark to this prized piece of land. Today, you can experience those influences firsthand by exploring Istanbul’s mahalles (neighborhoods). From the holy sites of Sultanahmet and the 19th-century European elegance of Beyoğlu to the high fashion of Nişantaşı, the vibrant café society of Kadıköy and the football-loving streets of Beşiktaş, it’s easy to see why travelers say that Istanbul isn’t just one city, but many cities within one.

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.

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.

Barcelona feels a bit surreal – appropriate, since Salvador Dali spent time here and Spanish Catalan architect Antoni Gaudí designed several of the city’s buildings. Stepping into Gaudí’s Church of the Sacred Family is a bit like falling through the looking glass - a journey that you can continue with a visit to Park Güell. Sip sangria at a sidewalk café in Las Ramblas while watching flamboyant street performers, then create your own moveable feast by floating from tapas bar to tapas bar.

So many of Madrid’s buildings look like castles, you’ll think you’ve stumbled into a fairytale. Even City Hall is astounding, with its white pinnacles and neo-Gothic features. A self-guided architecture tour can begin by the great bear statue in the central Puerta del Sol. Wander by the fanciful Royal Palace before absorbing the natural beauty of Retiro Park, then visit one of the city’s many museums. You could happily cap off each day by nibbling on forkfuls of paella while sipping Spanish rioja.

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.

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.