Ischia (Italian pronunciation: [ˈiskia]) is a volcanic island in the Tyrrhenian Sea, at the northern end of the Gulf of Naples. The roughly trapezoidal island lies about 30 km from Naples and measures around 10 km east to west and 7 km north to south with a 34 kilometres (21 mi) coastline and a surface area of 46.3 square kilometres (17.9 sq mi). It is almost entirely mountainous, with the highest peak being Mount Epomeo at 788 meters. The island has a population of over 60,000 people. Ischia Porto is the name of the main comune of the island. Other community areas include Barano d'Ischia, Casamicciola Terme, Forio, Lacco Ameno and Serrara Fontana. The main industry is tourism, centering on thermal spas that cater mostly to European (especially German) and Asian tourists eager to enjoy the fruits of the island's natural volcanic activity, its thermal hot springs, and its volcanic mud. For many of the inhabitants on the Italian-speaking island, German and English are second languages. This is because of the large number of German- and English-speaking tourists who visit the island each year.