Hedonistic and historic, Eivissa (Ibiza, in Castilian) is a city jam-packed with cafés, nightspots, and trendy shops; looming over it are the massive stone walls of Dalt Vila —the medieval city declared a UNESCO World Heritage site in 1999—and its Gothic cathedral. Squeezed between the north walls of the old city and the harbor is Sa Penya, a long labyrinth of stone-paved streets that offer some of the city's best offbeat shopping, snacking, and exploring. The tourist information office on Vara de Rey has a useful map of walks through the old city.

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.

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.

Livorno is a gritty city with a long and interesting history. In the early Middle Ages it alternately belonged to Pisa and Genoa. In 1421 Florence, seeking access to the sea, bought it. Cosimo I (1519–74) started construction of the harbor in 1571, putting Livorno on the map. After Ferdinando I de' Medici (1549–1609) proclaimed Livorno a free city, it became a haven for people suffering from religious persecution; Roman Catholics from England and Jews and Moors from Spain and Portugal, among others, settled here. The Quattro Mori (Four Moors), also known as the Monument to Ferdinando I, commemorates this. (The statue of Ferdinando I dates from 1595, the bronze Moors by Pietro Tacca from the 1620s.)In the following centuries, and particularly in the 18th, Livorno boomed as a port. In the 19th century the town drew a host of famous Britons passing through on their grand tours. Its prominence continued up to World War II, when it was heavily bombed. Much of the town's architecture, therefore, postdates the war, and it's somewhat difficult to imagine what it might have looked like before. Livorno has recovered from the war, however, as it's become a huge point of departure for container ships, as well as the only spot in Tuscany for cruise ships to dock for the day.Most of Livorno's artistic treasures date from the 17th century and aren't all that interesting unless you dote on obscure baroque artists. Livorno's most famous native artist, Amedeo Modigliani (1884–1920), was of much more recent vintage. Sadly, there's no notable work by him in his hometown.There may not be much in the way of art, but it's still worth strolling around the city. The Mercato Nuovo, which has been around since 1894, sells all sorts of fruits, vegetables, grains, meat, and fish. Outdoor markets nearby are also chock-full of local color. The presence of Camp Darby, an American military base just outside town, accounts for the availability of many American products.If you have time, Livorno is worth a stop for lunch or dinner at the very least.

Cannes is pampered with the luxurious year-round climate that has made it one of the most popular resorts in Europe. Cannes was an important sentinel site for the monks who established themselves on Île St-Honorat in the Middle Ages. Its bay served as nothing more than a fishing port until in 1834 an English aristocrat, Lord Brougham, fell in love with the site during an emergency stopover with a sick daughter. He had a home built here and returned every winter for a sun cure—a ritual quickly picked up by his peers. Between the popularity of Le Train Blue transporting wealthy passengers from Calais, and the introduction in 1936 of France's first paid holidays, Cannes became the destination, a tasteful and expensive breeding ground for the upper-upscale.Cannes has been further glamorized by the ongoing success of its annual film festival, as famous as Hollywood's Academy Awards. About the closest many of us will get to feeling like a film star is a stroll here along La Croisette, the iconic promenade that gracefully curves the wave-washed sand coastline, peppered with chic restaurants and prestigious private beaches. This is precisely the sort of place for which the French invented the verb flâner (to dawdle, saunter): strewn with palm trees and poseurs, its fancy boutiques and status-symbol grand hotels—including the Carlton, the legendary backdrop to Grace Kelly in To Catch a Thief —all vying for the custom of the Louis Vuitton set. This legend is, to many, the heart and soul of the Côte d'Azur. 

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.