THE FIRST THING that must be said about the ancient town of Civita di Bagnoregio, just two hours away from Rome and Florence, is that it is beautiful. From a distance, it looks literally otherworldly: The town sits so high atop a perilously steep pinnacle of eroding volcanic rock that it seems as if it’s perched upon clouds rather than tethered to the earth. Its very sediment is strafed with 2,500 years of architectural history: Etruscan caves, ancient remains, medieval dwellings and Renaissance villas.

Originally a center along ancient trade routes, Civita di Bagnoregio was prosperous from Roman times through the late Middle Ages. But after a devastating earthquake in 1695, most residents fled for lower ground, and so began the city’s long decline. By the end of World War II, nearly all of its inhabitants had left in search of work in cities or abroad. For the last half century, its population has hovered around 10 or so full-time residents.