Potsdam was the residence of the Prussian kings and German Kaisers until 1918. It is the site of the parks and palaces of Sanssouci, the largest World Heritage Site in Germany. The city is now the capital of the German federal state of Brandenburg and a home to three public colleges and a major film production studio.

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.

Lille is an architectural feast with strong Flemish influences from the Grand Place to the basilica of Notre Dame de la Treille to the quiet streets of row houses and gardens. For art buffs, Lille is home to the Musee d'Art Moderne and the Palais des Beaux Arts. Children will enjoy the Parc de Zoologique. Savvy travelers know that Lille has a fine public transit system, making this historical hotspot a pleasure to visit.

The promise of sun, sea, and sangria continues to draw visitors to Palmanova, though the resort town offers more than just revelry. Sports facilities and scenic surrounds provide plenty of active options throughout the year, while the waterfront promenade boasts modern cafés, hotels, and bars.

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.