Piazza Navona, one of the most beautifully baroque sites in all Rome, is an ocher-colored gem, unspoiled by new buildings or traffic. Its shape results from the ruins of the Stadium of Domitian, lying underneath. Great chariot races were once held here (some rather unusual, such as the one in which the head of the winning horse was lopped off as it crossed the finish line and was then carried by runners to be offered as a sacrifice by the Vestal Virgins atop the Capitoline). In medieval times, the popes used to flood the piazza to stage mock naval encounters. Today the piazza is packed with vendors and street performers, and lined with pricey cafes where you can enjoy a cappuccino or gelato and indulge in unparalleled people-watching.

Besides the twin-towered facade of 17th-century Santa Agnes, the piazza boasts several baroque masterpieces. The best known, in the center, is Bernini's Fountain of the Four Rivers (Fontana dei Quattro Fiumi), whose four stone personifications symbolize the world's greatest rivers: the Ganges, Danube, della Plata, and Nile. It's fun to try to figure out which is which. (Hint: The figure with the shroud on its head is the Nile, so represented because the river's source was unknown at the time.) At the south end is the Fountain of the Moor (Fontana del Moro), also by Bernini. The Fountain of Neptune (Fontana di Nettuno), which balances that of the Moor, is a 19th-century addition; it was restored after a demented 1997 attack by two men who broke off the tail of one of its sea creatures.