"When one wanted to arrive overnight at the incomparable, the fabulous, the like-nothing-else-in-the-world, where was it one went?" wrote Thomas Mann. "Why obviously . . . Venice." Italy's floating city, fragile as colored glass, has long been loved too well. Each year 2.3 million boisterous and devoted suitors importune this village of 79,000, clogging its narrow walkways, cluttering its wide canals, disturbing its hushed churches and driving its harried residents to distraction. Last summer when 200,000 fans camped in the Piazza San Marco for a Pink Floyd concert, it took the Italian army three days to clean up.
The toll that...