Pozzuoli, a city of Southern Italy, on the Bay of Naples, 7 miles W. of Naples, with which it is connected by tramway, a city particularly interesting from its numerous memorials of classic ages. Its cathedral was the Temple of Augustus. The Temple of Serapis or Serapeum had a rectangular colonnade of twenty-four pillars, surrounding a round temple with sixteen pillars. Some have alleged that the outer enclosure surrounded a market-place. Some of the pillars still standing are much eaten into by the lithodomus mollusc (see BORING ANIMALS), showing that this volcanic coast was for a considerable time submerged to a depth of 13 feet beneath the sea, and subsequently upheaved again. Part of the ruins are still under the sea-level. There are the remains of an amphitheatre in which Nero fought as a gladiator, and which could seat 30,000 spectators; in it wild beasts refused to injure St Januarius and his companions, thrown to them by persecutors. There are also remains of temples to Diana and Neptune, and of the ancient harbour of Puteoli. Behind the town is the Solfatara (anciently called Forum Vulcani, as being the entrance to Vulcan's forge), a half-extinct volcano, from which issue currents of hot sulphureous gases, inhaled by sufferers with chest complaints, and springs of saline water, used as a remedy for cutaneous diseases. In the neighbourhood are Avernus (q.v.); the royal (Italian) hunting-lodge Astoni; Lake Lucrinus, celebrated for its oysters; the ruins of Baie (q.v.) and Cumæ (q.v.); and the Lake of Agnano, with the Grotta del Cane (q.v.). Of a very different interest are the military engineering works, the Stabilimento Armstrong, a little to the west of Pozzuoli; this is a branch of the famous Armstrong works at Elswick, near Newcastle, established here (1888-90) with the support of the Italian government. Pop. 11,967. The ancient Puteoli was made a Roman colony in 194 B.C. Towards the end of the republican period it became virtually the port of Rome, and during the empire was the first emporium of commerce in Italy.
Puteoli was destroyed by Alaric, Genserich, and Totila, and, though rebuilt by the Byzantine Greeks, it was sacked by the Saracens (10th century) and the Turks (1550), and ruined by earthquakes (1198 and 1538). St Paul landed there.—For the volcanic earth found here and elsewhere, and called Pozzuolana or Puzzolana, see CEMENTS.