ISCHIA (Gr. ILO7pcokaa, "the apes' island," Lat. Aenaria, in poetry Inarime), an island off the coast of Campania, Italy, province of Naples, 16 m. S.W. of Naples and 7 m. S.W. of the Capo Miseno, the nearest point of the mainland. Pop. (1921) 27,631. It is situated at the west extremity of the gulf of Naples, and is the largest island near Naples, measuring about 19 m. in circumference and 26 sq.m. in area. It belongs to the same vol canic system as the mainland near it, and the Monte Epomeo (anc. 'Er-cord's, viewpoint), the highest point of the island (2,588 ft.), lies on the N. edge of the principal crater, which is surrounded by twelve smaller cones. The island was occupied by Greek settlers but its Eretrian and Chalcidian inhabitants abandoned it about 500 B.C. owing to an eruption, and it is said to have been deserted almost at once by the greater part of the garrison which Hieron I. of Syracuse had placed there about 470 B.C., owing to the same cause. Later on it came into the possession of Naples, but passed into Roman hands in 326, when Naples herself lost her independence.
Several eruptions are recorded in Roman times. The last of which we have any knowledge occurred in 1301, but the island was visited by earthquakes in 1881 and 1883, 1,700 lives being lost in the latter year, when the town of Casamicciola on the north side of the island was almost entirely destroyed. The hot springs
(147°), are alkaline and saline, and are much visited by bathers, especially in summer. They were known in Roman times, and many votive altars dedicated to Apollo and the nymphs have been found. The island is mountainous, beautiful and fertile. Wine, corn, oil and fruit are produced, especially the former, while the mountain slopes are clothed with woods. Tiles and pottery are made. Straw-plaiting is a considerable industry at Lacco; and a certain amount of fishing is also done. The potter's clay of Ischia served for the ancient potteries of Cumae and Puteoli.
The chief towns are Ischia on the E. coast, capital and seat of a bishop (pop. in 1921, town, 2,825; commune, 7,815), with a 15th century castle, to which Vittoria Colonna retired after the death of her husband in 1525; Casamicciola (pop. in 1921, town, 2,69o; commune, 3,375) on the north, and Forio on the west coast (pop. in 1921, town, 2,476; commune, 5,813). There is regular communication with Naples, both by steamer direct, and also by steamer to Torregaveta, 2 m. W.S.W. of Baiae and 121 m.
W.S.W. of Naples, and thence by rail. (T. A.)