LOST ROMAN RESORT

In the Bay of Naples, miles of ruins recall the splendor of ancient imperial holidays

- SAMIR S. PATEL

POMPEII GETS ALL THE scientific and public attention, and it's not hard to understand why. The city buried by the eruption of Mount Vesuvius in A.D. 79 provides an endless source of artistic marvels and archaeological insight, and the cone-shaped stratovolcano still looms over Naples with familiar menace. But just on the other side of Naples' modern sprawl is a kind of shadow Pompeii called Baiae, another ancient town lost to volcanic activity-but not due to a sudden cataclysm. Once a legendary playground for Rome's elite, Baiae slowly sank to a watery end.

Thousands of years before Baiae was known as a resort destination, it would have been the worst place in the world to be. Around 39,000 years ago, the Gulf of Pozzuoli, where Baiae was eventually founded, exploded with 100 times the power of Vesuvius. The waters of the gulf, about 10 miles west of Naples, and the land surrounding it cover a supervolcano known today as the Campi Flegrei, or Phlegraean Fields, meaning the "burning" or "fiery" fields. The caldera is eight miles across, shot through with faults and speckled with 24 craters from smaller bursts on land and underwater. The volcano erupted again around 15,000 years ago, creating vast deposits of the stone called Neapolitan yellow

A mosaic floor with a geometric pattern made of black and white squares of marble called tesserae now sits at the bottom of the Gulf of Pozzuoli off the modern Italian town of Baia. The floor once belonged to a sumptuous seaside home called the Villa with the Porch Entrance in the ancient resort of Baiae tuff, which fronts many of Naples' historic buildings.

The Campi Flegrei has not erupted with that kind of force since but has nonetheless continued to shape the area. Its craters formed inviting basins for Roman ports, its geothermal activity fed hot springs that drew travelers and emperors alike, and its restlessness reshaped the topography and shoreline.