Cagliari,Palermo,Valletta,Barcelona

Known in Sardinia as Casteddu, the island's capital has steep streets and impressive Italianate architecture, from modern to medieval. This city of nearly 160,000 people is characterized by a busy commercial center and waterfront with broad avenues and arched arcades, as well as by the typically narrow streets of the old hilltop citadel (called, simply, “Castello”). The Museo Archeologico makes a good starting point to a visit. The imposing Bastione di Saint Remy and Mercato di San Benedetto (one of the best fish markets in Italy) are both musts.

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.