Baia

Two thousand years ago the shore of Baia was the most fashionable stretch of coast in the Roman world. From the first century BC the senatorial elite and then the emperors built seaside villas, terraced gardens and lavish bath halls here, on the inner slope of an old volcanic crater in the Phlegraean Fields west of Naples. Marius, Lucullus and Pompey all spent time on this bay, Julius Caesar owned a villa, Nero built here, and Hadrian died at Baiae in AD 138. Roman writers from Seneca to Propertius treated the resort as a byword for luxury and loose living, which only added to its pull.

What makes Baia extraordinary today is that the ancient town survives on two levels. On the hillside, a terraced complex of villas and baths climbs above the modern harbour, with mosaics, stucco and vaulted halls still in place. Its showpiece is the so-called Temple of Mercury, in reality the cold pool of a bath building from the late Republic: its concrete dome, about 21.5 metres across, was the widest in the world until the Pantheon in Rome surpassed it, and it is often cited as the oldest surviving concrete dome. The "Temples" of Venus and Diana are likewise great domed bath halls, the first probably commissioned under Hadrian. Below the waterline lies the rest of the town. Bradyseism, the slow rise and fall of the ground in this volcanic area, pulled the lower quarter into the sea from late antiquity onward, and today streets, villa floors and statues rest a few metres under the surface of the bay.

That sunken city has been a protected underwater archaeological park since 2002, one of very few in the Mediterranean. Its most celebrated find came in 1969, when divers off Punta Epitaffio located marble statues from the banqueting hall of a villa belonging to the emperor Claudius, decorated as a sea cave with a group showing Ulysses offering wine to the Cyclops. The originals now stand in the archaeological museum of the Campi Flegrei inside the Castle of Baia, a fortress raised in the 16th century under the Spanish viceroy Pedro de Toledo on the headland above the bay, while copies have been returned to the seabed. The modern village of Baia is a small seaside district of Bacoli, and the ruins sit right beside its fishing harbour.

Getting there

Baia lies in the municipality of Bacoli, about 2 km from its centre, on the western side of the Gulf of Pozzuoli. The nearest airport is Naples International Airport (NAP), about 20 km to the east. Baia has its own station on the Cumana railway, the local line that runs from Montesanto in central Naples through Pozzuoli to Torregaveta.