BAIAE, ancient city, Campania, Italy, i om. W. of Neapolis, on the Sinus Baianus, a bay on the west coast of the gulf of Puteoli. The grave of Baios, helmsman of Ulysses, was shown there ; it was originally, perhaps, the harbour of Cumae. Its warm sulphur springs are remarkable for their variety and curative properties (Pliny, Hist. Nat. xxxi. 4) ; it has mild climate and luxuriant vegetation. In Strabo's day it was as large as Puteoli. Julius Caesar possessed a villa here, of which there are probably remains on the ridge above the i6th-century castle. Nero built a huge villa probably on the castle site. Hadrian died in Caesar's villa in A.D. 138, and Alexander Severus erected large buildings for his mother. Baiae formed part of the territory of Cumae. Its luxury and immorality were often censured.
Near Baiae was the villa resort of Bauli, so called from the (3ocuAta (stalls) in which the oxen of Geryon were concealed by Hercules. By some it is identified with the modern village of Bacoli (presumed similarity of name), 2m. S.S.E. of Baiae; by others with the Punta dell'Epitaffio, im. N.E. of Baiae. At Bauli, Pompey and Hortensius possessed villas, the former on the hills, the latter on the shores of the Lacus Lucrinus, remarkable for its tame lampreys and as the scene of the dialogue in the second hook of Cicero's Academica Priora; it afterwards became imperial property and was the scene of Agrippina's murder by Nero. It was from Bauli to Puteoli that Caligula built his bridge of boats. Baiae has three large and lofty domed buildings, two octagonal, one circular, and all circular in the interior, popularly called temples but really baths. Fine fragments of Flavian architecture and sculpture have been found in the bay near them. The Punta dell'Epitaffio also is covered with remains ; to the north of Bacoli is a small theatre, called the tomb of Agrippina; under the village are the ruins of a large villa ; to the east the remains of a large water reservoir, the so-called Cento Camerelle ; to the south an other with vaulted ceiling, the piscina mirabilis, measuring 23o by 85 feet. The villa of Marius, bought by Lucullus, and afterwards in the possession of the imperial house, was the scene of the death of Tiberius. It is sometimes spoken of as Baiana, sometimes as Misenensis and is perhaps to be sought at Bacoli. Baiae was devastated by the Saracens in the 8th century and entirely de serted on account of malaria in 150o.