1911 Encyclopædia Britannica/Ponza
PONZA (anc. Pontiae), the principal of a small group of islands belonging to Italy. Pop. (1901), 4621. The group is of volcanic origin, and includes Palmarola (anc. Palmaria), Zannone (Sinonia), Ventonene (Pandateria, pop. in 1901, 1986) and San Stefano. It is situated about 20 m. S. of Monte Circeo and 70 m. W. of Naples, and belongs partly to the province of Caserta and partly to that of Naples (Ventonene). There is regular communication with Naples by steamer, and in summer with Anzio. The islands rise to a height of about 70 ft. above sea-level. They are now penal settlements, and their isolated character led to their being similarly used in ancient times. A colony with Latin rites was founded on Pontiae in 313 B.C. Nero, Germanicus's eldest son, and the sisters of Caligula, were confined upon it; while Pandateria was the place of banishment of Julia, daughter of Augustus, of her daugher Agrippina the elder, and of Octavia, the divorced wife of Nero.