Spain, France, Italy, Malta

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.

Since being designated a European Capital of Culture for 2013, with an estimated €660 million of funding in the bargain, Marseille has been in the throes of an extraordinary transformation, with no fewer than five major new arts centers, a beautifully refurbished port, revitalized neighborhoods, and a slew of new shops and restaurants. Once the underdog, this time-burnished city is now welcoming an influx of weekend tourists who have colonized entire neighborhoods and transformed them into elegant pieds-à-terre (or should we say, mer). The second-largest city in France, Marseille is one of Europe's most vibrant destinations. Feisty and fond of broad gestures, it is also as complicated and as cosmopolitan now as it was when a band of Phoenician Greeks first sailed into the harbor that is today's Vieux Port in 600 BC. Legend has it that on that same day a local chieftain's daughter, Gyptis, needed to choose a husband, and her wandering eyes settled on the Greeks' handsome commander Protis. Her dowry brought land near the mouth of the Rhône, where the Greeks founded Massalia, the most important Continental shipping port in antiquity. The port flourished for some 500 years as a typical Greek city, enjoying the full flush of classical culture, its gods, its democratic political system, its sports and theater, and its naval prowess. Caesar changed all that, besieging the city in 49 BC and seizing most of its colonies. In 1214 Marseille was seized again, this time by Charles d'Anjou, and was later annexed to France by Henri IV in 1481, but it was not until Louis XIV took the throne that the biggest transformations of the port began; he pulled down the city walls in 1666 and expanded the port to the Rive Neuve (New Riverbank). The city was devastated by plague in 1720, losing more than half its population. By the time of the Revolution, Marseille was on the rebound once again, with industries of soap manufacturing and oil processing flourishing, encouraging a wave of immigration from Provence and Italy. With the opening of the Suez Canal in 1869, Marseille became the greatest boomtown in 19th-century Europe. With a large influx of immigrants from areas as exotic as Tangiers, the city quickly acquired the multicultural population it maintains to this day.

La Spezia is sometimes thought of as nothing but a large, industrialized naval port en route to the Cinque Terre and Portovenere, but it does possess some charm, and it gives you a look at a less tourist-focused part of the Riviera. Its palm-lined promenade, fertile citrus parks, renovated Liberty-style palazzos, and colorful balcony-lined streets make parts of La Spezia surprisingly beautiful. Monday through Saturday mornings, you can stroll through the fresh fish, produce, and local-cheese stalls at the outdoor market on Piazza Cavour, and on Friday take part in the busy flea market on Via Garibaldi. There's also Porto Mirabello, a newly built tourist port with a pool club, shops, and several restaurants that overlook the fleet of super-yachts.

Naples, in the Campania region, is Italy's third largest city. Its claim to fame is the spectacular location along one of the world's most splendid bays, backed by the perfect cone of Mount Vesuvius. In addition to its beautiful setting, Naples' surprises with other outstanding attractions such as the Royal Palace, San Carlos Opera House, the impressive National Archaeological Museum and the Castel Nuovo, dating from the 13th-century. The city's central area is best explored on foot. Chaotic traffic conditions make driving around the city a very frustrating experience. Naples provides a convenient starting point for trips to such favored destinations as Pompeii, Herculaneum and Mount Vesuvius. The Isle of Capri can be reached via a 45-minute hydrofoil service. The region of Campania was home to Greeks settlers some 300 years before Rome was founded. Pompeii, too, was a Greek town before being conquered by the Romans during the 5th century BC. It was under the Romans that Pompeii flourished and grew prosperous. When Mount Vesuvius erupted in 79 AD, the population of 20,000 was wiped out, but dozens of buildings were preserved under layers of cinder more than 20 feet deep. The most important finds from Pompeii are displayed in Naples' National Archaeological Museum. A visit here will no doubt enhance a visit to ancient Pompeii.

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).

Malta's capital, the minicity of Valletta, has ornate palaces and museums protected by massive fortifications of honey-color limestone. Houses along the narrow streets have overhanging wooden balconies for people-watching from indoors. Generations ago they gave housebound women a window on the world of the street. The main entrance to town is through the City Gate (where all bus routes end), which leads onto Triq Repubblika (Republic Street), the spine of the grid-pattern city and the main shopping street. Triq Mercante (Merchant Street) parallels Repubblika to the east and is also good for strolling. From these two streets, cross streets descend toward the water; some are stepped. Valletta's compactness makes it ideal to explore on foot. City Gate and the upper part of Valletta are experiencing vast redevelopment that includes a new Parliament Building and open-air performance venue. The complex, completed mid-2013, has numerous pedestrian detours in place along with building noise and dust. Before setting out along Republic Street, stop at the tourist information office on Merchant Street for maps and brochures.

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.