CIVITA VECCHIA, a seaport town and episcopal see of Italy, in the province of Rome, 50 m. N.W. by rail and 35 m. direct from the city of Rome. Pop. (1871) 8143; (1901) 17,589. It is the ancient Centum Cellae, founded by Trajan. Interesting descriptions of it are given by Pliny the Younger (Epist. vi. 31) and Rutilius Namat. i. 237. The modern harbour works rest on the ancient foundations, and near it the cemetery of detachments of the Classes Misenensis and Ravennas has been found (Corp. Inscr. Lat. vol. xi., Berlin, 1888, pp. 3520 seq.). Remains of an aqueduct and other Roman buildings are preserved; the imperial family had a villa here. Procopius mentions it in the 6th century as a strong and populous place, but it was destroyed in 813 by the Saracens. Leo IV. erected a new city for the inhabitants on the site where they had taken refuge, about 8 m. N.N.E. of Civita Vecchia towards the hills, near La Farnesina, where its ruins may still be seen; the city walls and some of the streets and buildings may be traced, and an inscription (which must have stood over one of the city gates) recording its foundation has been discovered. It continued to exist under the name Cencelle as a feudal castle until the 15th century. In the meantime, however, the inhabitants returned to the old town by the shore in 889 and rebuilt it, giving it the name Civitas Vetus, the modern Civita Vecchia (see O. Marucchi in Nuovo Bullettino di archeologia cristiana, vi., 1900, p. 195 seq.). In 1508 Pope Julius II. began the construction of the castle from the designs of Bramante, Michelangelo being responsible for the addition of the central tower. It is considered by Burckhardt the finest building of its kind. Pius IV. added a convict prison. The arsenal was built by Alexander VII. and designed by Bernini. Civita Vecchia was the chief port of the Papal State and has still a considerable trade. There are cement factories in the town, and calcium carbide is an important article of export. The principal imports are coal, cattle for the home markets, and fire-bricks from the United Kingdom. Three miles N.E. were the Aquae Tauri, warm springs, now known as Bagni della Ferrata: considerable remains of the Roman baths are still preserved. About 1 m. W. of these are other hot springs, those of the Ficoncella, also known in Roman times.