History

From the late Roman Republic through the Imperial period, Baiae was the resort destination of Rome’s elite. The thermal springs of the Phlegraean Fields had been exploited since at least the 2nd century BC, and by the 1st century BC the coastline had become the most concentrated display of luxurious private architecture in the ancient world. The villas were remarkable: multi-storey maritime residences with heated bathing pools cooled by seawater, underground heated chambers, fish ponds stocked with moray eels and sea bream, and sea-facing porticoes. Horace wrote: nullus in orbe sinus Baiis praelucet amoenis (no bay in the world shines more brightly than lovely Baiae). Julius Caesar maintained his principal villa here; Caligula had engineers build a floating bridge of boats across the bay to fulfil a prophecy that he would no more become emperor than ride across it on horseback.

The same volcanic activity that made Baiae desirable ultimately destroyed it. The Phlegraean Fields caldera is a supervolcanic system covering approximately 100 square kilometres that periodically rises and falls as magma pressures change underground. Between the 4th and 8th centuries AD, the ground beneath the northern Bay of Naples subsided by several metres, gradually submerging the coastal villas. By the 8th century AD the waterfront districts were entirely underwater. Systematic underwater archaeological investigation began in the 1950s; the Parco Sommerso di Baia was formally established as a protected marine archaeological area in 2002.