Civitavecchia, Palermo, Barcelona, Valencia

Italy's vibrant capital lives in the present, but no other city on earth evokes its past so powerfully. For over 2,500 years, emperors, popes, artists, and common citizens have left their mark here.

Archaeological remains from ancient Rome, art-stuffed churches, and the treasures of Vatican City vie for your attention, but Rome is also a wonderful place to practice the Italian-perfected il dolce far niente, the sweet art of idleness. Your most memorable experiences may include sitting at a caffè in the Campo de' Fiori or strolling in a beguiling piazza.

Once the intellectual capital of southern Europe, Palermo has always been at the crossroads of civilization. Favorably situated on a crescent-shaped bay at the foot of Monte Pellegrino, it has attracted almost every culture touching the Mediterranean world. To Palermo's credit, it has absorbed these diverse cultures into a unique personality that is at once Arab and Christian, Byzantine and Roman, Norman and Italian. The city's heritage encompasses all of Sicily's varied ages, but its distinctive aspect is its Arab-Norman identity, an improbable marriage that, mixed in with Byzantine and Jewish elements, created some resplendent works of art. No less noteworthy than the architecture is Palermo's chaotic vitality, on display at some of Italy's most vibrant outdoor markets, public squares, street bazaars, and food vendors, and above all in its grand climax of Italy's most spectacular passeggiata (the leisurely social stroll along the principal thoroughfare).

The infinite variety of street life, the nooks and crannies of the medieval Barri Gòtic, the ceramic tile and stained glass of Art Nouveau facades, the art and music, the throb of street life, the food (ah, the food!)—one way or another, Barcelona will find a way to get your full attention. The capital of Catalonia is a banquet for the senses, with its beguiling mix of ancient and modern architecture, tempting cafés and markets, and sun-drenched Mediterranean beaches. A stroll along La Rambla and through waterfront Barceloneta, as well as a tour of Gaudí's majestic Sagrada Famíliaand his other unique creations, are part of a visit to Spain's second-largest city. Modern art museums and chic shops call for attention, too. Barcelona's vibe stays lively well into the night, when you can linger over regional wine and cuisine at buzzing tapas bars.

Valencia, Spain's third-largest municipality, is a proud city with a thriving nightlife and restaurant scene, quality museums, and spectacular contemporary architecture, juxtaposed with a thoroughly charming historic quarter, making it a popular destination year in year out. During the Civil War, it was the last seat of the Republican Loyalist government (1935–36), holding out against Franco’s National forces until the country fell to 40 years of dictatorship. Today it represents the essence of contemporary Spain—daring design and architecture along with experimental cuisine—but remains deeply conservative and proud of its traditions. Though it faces the Mediterranean, Valencia's history and geography have been defined most significantly by the River Turia and the fertile huerta that surrounds it.The city has been fiercely contested ever since it was founded by the Greeks. El Cid captured Valencia from the Moors in 1094 and won his strangest victory here in 1099: he died in the battle, but his corpse was strapped into his saddle and so frightened the besieging Moors that it caused their complete defeat. In 1102 his widow, Jimena, was forced to return the city to Moorish rule; Jaume I finally drove them out in 1238. Modern Valencia was best known for its frequent disastrous floods until the River Turia was diverted to the south in the late 1950s. Since then the city has been on a steady course of urban beautification. The lovely bridges that once spanned the Turia look equally graceful spanning a wandering municipal park, and the spectacularly futuristic Ciutat de les Arts i les Ciències (City of Arts and Sciences), most of it designed by Valencia-born architect Santiago Calatrava, has at last created an exciting architectural link between this river town and the Mediterranean. If you're in Valencia, an excursion to Albufera Nature Park is a worthwhile day trip.