Aichi (Īˈchē) [key], prefecture (1990 pop. 6,690,440), 1,962 sq mi (5,082 sq km), central Honshu, Japan. Bounded on the S and W by Ise Bay, Aichi consists of a coastal plain (the Nobi Plain) and a mountainous, forested interior. It is drained by the Kiso River, an important source of hydroelectric power. Nagoya, the capital, and its surrounding suburbs make up the Chukyo Industrial Region, which is Japan's third largest industrial concentration. It produces automobiles, textiles, ceramics, machinery, and chemicals. Aichi's major industrial centers are Nagoya, Toyohashi, Okazaki, Ichinomiya, Toyota, Tanjo, and Seto. Agricultural products and raw silk are produced, and lignite and quartz are mined. Expo 2005 was held in Aichi. Central Japan International Airport is located nearby on an artificial island in Ise Bay near Tokoname.