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.

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.

The only city in the world that can lay claim to straddling two continents, Istanbul—once known as Constantinople, capital of the Byzantine and then the Ottoman Empire—has for centuries been a bustling metropolis with one foot in Europe and the other in Asia. Istanbul embraces this enviable position with both a certain chaos and inventiveness, ever evolving as one of the world’s most cosmopolitan crossroads. It’s often said that Istanbul is the meeting point of East and West, but visitors to this city built over the former capital of two great empires are likely to be just as impressed by the juxtaposition of old and new. Office towers creep up behind historic palaces, women in chic designer outfits pass others wearing long skirts and head coverings, peddlers’ pushcarts vie with battered old Fiats and shiny BMWs for dominance of the noisy, narrow streets, and the Grand Bazaar competes with modern shopping malls. At dawn, when the muezzin's call to prayer resounds from ancient minarets, there are inevitably a few hearty revelers still making their way home from nightclubs and bars. Most visitors to this sprawling city of more than 14 million will first set foot in the relatively compact Old City, where the legacy of the Byzantine and Ottoman empires can be seen in monumental works of architecture like the brilliant Aya Sofya and the beautifully proportioned mosques built by the great architect Sinan. Though it would be easy to spend days, if not weeks, exploring the wealth of attractions in the historical peninsula, visitors should make sure also to venture elsewhere in order to experience the vibrancy of contemporary Istanbul. With a lively nightlife propelled by its young population and an exciting arts scene that’s increasingly on the international radar—thanks in part to its stint as the European Capital of Culture in 2010—Istanbul is truly a city that never sleeps. It’s also a place where visitors will feel welcome: Istanbul may be on the Bosphorus, but at heart it’s a Mediterranean city, whose friendly inhabitants are effusively social and eager to share what they love most about it.

The only city in the world that can lay claim to straddling two continents, Istanbul—once known as Constantinople, capital of the Byzantine and then the Ottoman Empire—has for centuries been a bustling metropolis with one foot in Europe and the other in Asia. Istanbul embraces this enviable position with both a certain chaos and inventiveness, ever evolving as one of the world’s most cosmopolitan crossroads. It’s often said that Istanbul is the meeting point of East and West, but visitors to this city built over the former capital of two great empires are likely to be just as impressed by the juxtaposition of old and new. Office towers creep up behind historic palaces, women in chic designer outfits pass others wearing long skirts and head coverings, peddlers’ pushcarts vie with battered old Fiats and shiny BMWs for dominance of the noisy, narrow streets, and the Grand Bazaar competes with modern shopping malls. At dawn, when the muezzin's call to prayer resounds from ancient minarets, there are inevitably a few hearty revelers still making their way home from nightclubs and bars. Most visitors to this sprawling city of more than 14 million will first set foot in the relatively compact Old City, where the legacy of the Byzantine and Ottoman empires can be seen in monumental works of architecture like the brilliant Aya Sofya and the beautifully proportioned mosques built by the great architect Sinan. Though it would be easy to spend days, if not weeks, exploring the wealth of attractions in the historical peninsula, visitors should make sure also to venture elsewhere in order to experience the vibrancy of contemporary Istanbul. With a lively nightlife propelled by its young population and an exciting arts scene that’s increasingly on the international radar—thanks in part to its stint as the European Capital of Culture in 2010—Istanbul is truly a city that never sleeps. It’s also a place where visitors will feel welcome: Istanbul may be on the Bosphorus, but at heart it’s a Mediterranean city, whose friendly inhabitants are effusively social and eager to share what they love most about it.

Having been controlled by Arabic, Venetian and Ottoman empires over the years - it's no surprise that Heraklion is a diverse patchwork of exotic cultures and historical treasures. Celebrated as the birthplace of the Spanish Renaissance artist, El Greco, you can visit to explore the storied ruins of the Minoan empire's capital, and unearth the rich cultural treasures that Crete’s bustling modern capital has to offer.

Katakolon could not seem less of a cruise port if it tried. A tiny enclave clinging to the western Peloponnese coast, it's a sleepy place except when ships dock. But it's a popular cruise destination because of its proximity to Olympia. Ancient Olympia was one of the most important cities in classical Greece. The Sanctuary of Zeus was the city's raison d'être, and attracted pilgrims from around the eastern Mediterranean, and later the city played host to Olympic Games, the original athletic games that were the inspiration for today's modern sporting pan-planetary meet. At the foot of the tree-covered Kronion hill, in a valley near two rivers, Katakolon is today one of the most popular ancient sites in Greece. If you don't want to make the trip to Olympia, then Katakolon is an ideal place for a leisurely Greek lunch while you watch the fishermen mend their nets, but there's just not much else to do there.

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.

Up until the end of World War I, Trieste was the only port of the vast Austro-Hungarian Empire and therefore a major industrial and financial center. In the early years of the 20th century, Trieste and its surroundings also became famous by their association with some of the most important names of Italian literature, such as Italo Svevo, and English and German letters. James Joyce drew inspiration from the city's multiethnic population, and Rainer Maria Rilke was inspired by the seacoast west of the city. Although it has lost its importance as a port and a center of finance, it has never fully lost its roll as an intellectual center. The streets hold a mix of monumental, neoclassical, and art-nouveau architecture built by the Austrians during Trieste's days of glory, granting an air of melancholy stateliness to a city that lives as much in the past as the present.