The Ischia volcanic complex forms a rectangular, 6 x 9 km island immediately SW of the Campi Flegrei area at the western side of the Bay of Naples. The eruption of the trachytic Green Tuff ignimbrite about 56,000 years ago was followed by caldera formation. The high point on the island, 789-m-high Monte Epomeo, is a volcanic horst composed of the Green Tuff ignimbrite deposit that was submerged after its eruption and then uplifted. Volcanism on the island has been significantly affected by tectonism that formed a series of horsts and grabens; at least 800 m of uplift has formed as a result of resurgent doming during past 33,000 years. Volcanism during the Holocene produced a series of pumiceous tephras, tuff rings, lava domes, and lava flows, and a major collapse of Mount Epomeo produced a large submarine debris-avalanche deposit. The latest eruption of Ischia, in 1302 AD, produced a spatter cone and the Arso lava flow, which reached the NE coast.