Siena

Historic center Siena is the Gothic city that stopped growing at the right moment, so its steep brick streets still pour down into the Piazza del Campo much as they did when the city was an independent republic. That square, where the Palio horse race is still run, is one of the great medieval public spaces, and the cathedral beside it rewards an hour inside. The historic center has been on UNESCO's list since 1995 and is closed to most traffic, so plan to park outside and walk in. Day-trip coaches fill the Campo by midday; stay the night and the alleys of the contrade, the city's old neighborhoods, are yours by evening.