Ischia (ēsˈkyä) [key], volcanic island (1991 pop. 16,013), 18 sq mi (47 sq km), Campania, S Italy, in the Tyrrhenian Sea between the Gulf of Gaeta and the Bay of Naples. Known as the Emerald Isle, it is a health resort and a tourist center, celebrated for its warm mineral springs and for its scenery. Fishing and farming are also pursued, and wine (Epomeo), tiles, and pottery are made. Settled in the 8th cent. B.C., the island was abandoned several times because of volcanic eruptions (the last of which occurred in 1301). There was a severe earthquake in 1883. Monte Epomeo (2,585 ft/788 m) is the island's highest point. Ischia, the main town, has an imposing 15th-century castle, constructed on foundations built by the Greeks in the 5th cent. B.C.