Corso and Spagna

Right at the top of everyone's sightseeing list is the great Rococo confection of the Trevi Fountain: the Elton John of hydrants tinkling tirelessly for its droves of fans. Legend has it that a coin in the water guarantees, courtesy Fortune Airways, a cut-price return—even the most rational of us may find it hard to resist throwing one in, just in case. The Trevi is Rome's most celebrated waterwork, and you can rest assured, you are not the only one who knows it. Once you've chucked your change, follow the crowds and get ready to take some very serious time to explore this neighborhood, which extends along the Corso, the ruler-straight avenue that divides central Rome neatly in half.

If Rome has a Main Street, it's Via del Corso, which is often jammed with swarms of Roman teenagers, in from the city's outlying districts for a ritual stroll that resembles a strutting migration of lemmings in blue jeans. The Corso begins at noisy, chaotic Piazza Venezia, the imperial-size hub of all this ostentation, presided over by the Vittoriano, also known as the Altare della Patria (Altar of the Nation), or, less piously, as the "typewriter," the "wedding cake," or the Eighth Hill of Rome. Sitting grandly off the avenue are the Palazzo Doria-Pamphilj and the Palazzo Colonna—two of the city's great art collections housed in magnificent family palaces.

Extending just east of Via del Corso, but miles away in style, Piazza di Spagna and its surrounding streets are where the elite meet. Back when, 19th-century artists used to troll the area around the Spanish Steps for models; today, it remains a magnet all day and well into the night for smooching Romans and camera-toting tourists. The density of high-fashion boutiques and trendy little shops leaves little room for residents—the closest thing to locals are the ladies loaded down with bags from Prada and tottering on Gucci stilettos. Lest you think the neighborhood is all Johnny-come-lately frivolity, stop into the Antico Caffè Greco, the one-time haunt of Franz Lizst, Mark Twain, and Hans Christian Andersen. It's been operating since 1760, making it one of the oldest caffè in the world. Prepare to linger.