A small, quiet, well-heeled city, Ravenna has brick palaces, cobblestone streets, magnificent monuments, and spectacular Byzantine mosaics. The high point in its civic history occurred in the 5th century, when Pope Honorious moved his court here from Rome. Gothic kings Odoacer and Theodoric ruled the city until it was conquered by the Byzantines in AD 540. Ravenna later fell under the sway of Venice, and then, inevitably, the Papal States.Because Ravenna spent much of its past looking east, its greatest art treasures show that Byzantine influence. Churches and tombs with the most unassuming exteriors contain within them walls covered with sumptuous mosaics. These beautifully preserved Byzantine mosaics put great emphasis on nature, which you can see in the delicate rendering of sky, earth, and animals. Outside Ravenna, the town of Classe hides even more mosaic gems.

Undoubtedly the most extraordinary island in the Aegean, crescent-shape Santorini remains a mandatory stop on the Cycladic tourist route—even if it's necessary to enjoy the sensational sunsets from Ia, the fascinating excavations, and the dazzling white towns with a million other travelers. Called Kállisti (the "Loveliest") when first settled, the island has now reverted to its subsequent name of Thira, after the 9th-century-BC Dorian colonizer Thiras. The place is better known, however, these days as Santorini, a name derived from its patroness, St. Irene of Thessaloniki, the Byzantine empress who restored icons to Orthodoxy and died in 802. You can fly conveniently to Santorini, but to enjoy a true Santorini rite of passage, opt instead for the boat trip here, which provides a spectacular introduction. After the boat sails between Sikinos and Ios, your deck-side perch approaches two close islands with a passage between them. The bigger one on the left is Santorini, and the smaller on the right is Thirassia. Passing between them, you see the village of Ia adorning Santorini's northernmost cliff like a white geometric beehive. You are in the caldera (volcanic crater), one of the world's truly breathtaking sights: a demilune of cliffs rising 1,100 feet, with the white clusters of the towns of Fira and Ia perched along the top. The bay, once the high center of the island, is 1,300 feet in some places, so deep that when boats dock in Santorini's shabby little port of Athinios, they do not drop anchor. The encircling cliffs are the ancient rim of a still-active volcano, and you are sailing east across its flooded caldera. On your right are the Burnt isles, the White isle, and other volcanic remnants, all lined up as if some outsize display in a geology museum. Hephaestus's subterranean fires smolder still—the volcano erupted in 198 BC, about 735, and there was an earthquake in 1956. Indeed, Santorini and its four neighboring islets are the fragmentary remains of a larger landmass that exploded about 1600 BC: the volcano's core blew sky high, and the sea rushed into the abyss to create the great bay, which measures 10 km by 7 km (6 mi by 4½ mi) and is 1,292 feet deep. The other pieces of the rim, which broke off in later eruptions, are Thirassia, where a few hundred people live, and deserted little Aspronissi ("White isle"). In the center of the bay, black and uninhabited, two cones, the Burnt Isles of Palea Kameni and Nea Kameni, appeared between 1573 and 1925. There has been too much speculation about the identification of Santorini with the mythical Atlantis, mentioned in Egyptian papyri and by Plato (who says it's in the Atlantic), but myths are hard to pin down. This is not true of old arguments about whether tidal waves from Santorini's cataclysmic explosion destroyed Minoan civilization on Crete, 113 km (70 mi) away. The latest carbon-dating evidence, which points to a few years before 1600 BC for the eruption, clearly indicates that the Minoans outlasted the eruption by a couple of hundred years, but most probably in a weakened state. In fact, the island still endures hardships: since antiquity, Santorini has depended on rain collected in cisterns for drinking and irrigating—the well water is often brackish—and the serious shortage is alleviated by the importation of water. However, the volcanic soil also yields riches: small, intense tomatoes with tough skins used for tomato paste (good restaurants here serve them); the famous Santorini fava beans, which have a light, fresh taste; barley; wheat; and white-skin eggplants.

Although the fishing boats still go out in good weather, Mykonos largely makes its living from tourism these days. The summer crowds have turned one of the poorest islands in Greece into one of the richest. Old Mykonians complain that their young, who have inherited stores where their grandfathers once sold eggs or wine, get so much rent that they have lost ambition, and in summer sit around pool bars at night with their friends, and hang out in Athens in winter when island life is less scintillating. Put firmly on the map by Jackie O in the 1960s, Mykonos town—called Hora by the locals—remains the Saint-Tropez of the Greek islands. The scenery is memorable, with its whitewashed streets, Little Venice, the Kato Myli ridge of windmills, and Kastro, the town's medieval quarter. Its cubical two- or three-story houses and churches, with their red or blue doors and domes and wooden balconies, have been long celebrated as some of the best examples of classic Cycladic architecture. Luckily, the Greek Archaeological Service decided to preserve the town, even when the Mykonians would have preferred to rebuild, and so the Old Town has been impressively preserved. Pink oleander, scarlet hibiscus, and trailing green pepper trees form a contrast amid the dazzling whiteness, whose frequent renewal with whitewash is required by law. Any visitor who has the pleasure of getting lost in its narrow streets (made all the narrower by the many outdoor stone staircases, which maximize housing space in the crowded village) will appreciate how its confusing layout was designed to foil pirates—if it was designed at all. After Mykonos fell under Turkish rule in 1537, the Ottomans allowed the islanders to arm their vessels against pirates, which had a contradictory effect: many of them found that raiding other islands was more profitable than tilling arid land. At the height of Aegean piracy, Mykonos was the principal headquarters of the corsair fleets—the place where pirates met their fellows, found willing women, and filled out their crews. Eventually the illicit activity evolved into a legitimate and thriving trade network. Morning on Mykonos town's main quay is busy with deliveries, visitors for the Delos boats, lazy breakfasters, and street cleaners dealing with the previous night's mess. In late morning the cruise-boat people arrive, and the shops are all open. In early afternoon, shaded outdoor tavernas are full of diners eating salads (Mykonos's produce is mostly imported); music is absent or kept low. In mid- and late afternoon, the town feels sleepy, since so many people are at the beach, on excursions, or sleeping in their air-conditioned rooms; even some tourist shops close for siesta. By sunset, people have come back from the beach, having taken their showers and rested. At night, the atmosphere in Mykonos ramps up. The cruise-boat people are mostly gone, coughing three-wheelers make no deliveries in the narrow streets, and everyone is dressed sexy for summer and starting to shimmy with the scene. Many shops stay open past midnight, the restaurants fill up, and the bars and discos make ice cubes as fast as they can. Ready to dive in? Begin your tour of Mykonos town (Hora) by starting out at its heart: Mando Mavrogenous Square.

It's no wonder that all roads lead to the fascinating and maddening metropolis of Athens. Lift your eyes 200 feet above the city to the Parthenon, its honey-color marble columns rising from a massive limestone base, and you behold architectural perfection that has not been surpassed in 2,500 years. But, today, this shrine of classical form dominates a 21st-century boomtown. To experience Athens—Athína in Greek—fully is to understand the essence of Greece: ancient monuments surviving in a sea of cement, startling beauty amid the squalor, tradition juxtaposed with modernity. Locals depend on humor and flexibility to deal with the chaos; you should do the same. The rewards are immense. Although Athens covers a huge area, the major landmarks of the ancient Greek, Roman, and Byzantine periods are close to the modern city center. You can easily walk from the Acropolis to many other key sites, taking time to browse in shops and relax in cafés and tavernas along the way. From many quarters of the city you can glimpse "the glory that was Greece" in the form of the Acropolis looming above the horizon, but only by actually climbing that rocky precipice can you feel the impact of the ancient settlement. The Acropolis and Filopappou, two craggy hills sitting side by side; the ancient Agora (marketplace); and Kerameikos, the first cemetery, form the core of ancient and Roman Athens. Along the Unification of Archaeological Sites promenade, you can follow stone-paved, tree-lined walkways from site to site, undisturbed by traffic. Cars have also been banned or reduced in other streets in the historical center. In the National Archaeological Museum, vast numbers of artifacts illustrate the many millennia of Greek civilization; smaller museums such as the Goulandris Museum of Cycladic Art Museum and the Byzantine and Christian Museum illuminate the history of particular regions or periods. Athens may seem like one huge city, but it is really a conglomeration of neighborhoods with distinctive characters. The Eastern influences that prevailed during the 400-year rule of the Ottoman Empire are still evident in Monastiraki, the bazaar area near the foot of the Acropolis. On the northern slope of the Acropolis, stroll through Plaka (if possible by moonlight), an area of tranquil streets lined with renovated mansions, to get the flavor of the 19th-century's gracious lifestyle. The narrow lanes of Anafiotika, a section of Plaka, thread past tiny churches and small, color-washed houses with wooden upper stories, recalling a Cycladic island village. In this maze of winding streets, vestiges of the older city are everywhere: crumbling stairways lined with festive tavernas; dank cellars filled with wine vats; occasionally a court or diminutive garden, enclosed within high walls and filled with magnolia trees and the flaming trumpet-shaped flowers of hibiscus bushes. Formerly run-down old quarters, such as Thission, Gazi and Psirri, popular nightlife areas filled with bars and mezedopoleia (similar to tapas bars), are now in the process of gentrification, although they still retain much of their original charm, as does the colorful produce and meat market on Athinas. The area around Syntagma Square, the tourist hub, and Omonia Square, the commercial heart of the city about 1 km (½ mi) northwest, is distinctly European, having been designed by the court architects of King Otho, a Bavarian, in the 19th century. The chic shops and bistros of ritzy Kolonaki nestle at the foot of Mt. Lycabettus, Athens's highest hill (909 feet). Each of Athens's outlying suburbs has a distinctive character: in the north is wealthy, tree-lined Kifissia, once a summer resort for aristocratic Athenians, and in the south and southeast lie Glyfada, Voula, and Vouliagmeni, with their sandy beaches, seaside bars, and lively summer nightlife. Just beyond the city's southern fringes is Piraeus, a bustling port city of waterside fish tavernas and Saronic Gulf views.

Split's ancient core is so spectacular and unusual that a visit is more than worth your time. The heart of the city lies within the walls of Roman emperor Diocletian's retirement palace, which was built in the 3rd century AD. Diocletian, born in the nearby Roman settlement of Salona in AD 245, achieved a brilliant career as a soldier and became emperor at the age of 40. In 295 he ordered this vast palace to be built in his native Dalmatia, and when it was completed he stepped down from the throne and retired to his beloved homeland. Upon his death, he was laid to rest in an octagonal mausoleum, around which Split's magnificent cathedral was built.In 615, when Salona was sacked by barbarian tribes, those fortunate enough to escape found refuge within the stout palace walls and divided up the vast imperial apartments into more modest living quarters. Thus, the palace developed into an urban center, and by the 11th century the settlement had expanded beyond the ancient walls.Under the rule of Venice (1420–1797), Split—as a gateway to the Balkan interior—became one of the Adriatic's main trading ports, and the city's splendid Renaissance palaces bear witness to the affluence of those times. When the Habsburgs took control during the 19th century, an overland connection to Central Europe was established by the construction of the Split–Zagreb–Vienna railway line.After World War II, the Tito years saw a period of rapid urban expansion: industrialization accelerated and the suburbs extended to accommodate high-rise apartment blocks. Today the historic center of Split is included on UNESCO's list of World Heritage Sites.

A small, quiet, well-heeled city, Ravenna has brick palaces, cobblestone streets, magnificent monuments, and spectacular Byzantine mosaics. The high point in its civic history occurred in the 5th century, when Pope Honorious moved his court here from Rome. Gothic kings Odoacer and Theodoric ruled the city until it was conquered by the Byzantines in AD 540. Ravenna later fell under the sway of Venice, and then, inevitably, the Papal States.Because Ravenna spent much of its past looking east, its greatest art treasures show that Byzantine influence. Churches and tombs with the most unassuming exteriors contain within them walls covered with sumptuous mosaics. These beautifully preserved Byzantine mosaics put great emphasis on nature, which you can see in the delicate rendering of sky, earth, and animals. Outside Ravenna, the town of Classe hides even more mosaic gems.