OAHU

island, Honolulu county, Hawaii, U.S., separated from the islands of Kauai (northwest) and Molokai (southeast) by the Kauai and Kaiwi channels. Of volcanic origin with an area of 607 square miles (1,574 square km), Oahu is third in size and the most populated of the Hawaiian Islands. Two parallel mountain groups, the Koolau Range and Waianae Ranges, are connected by a central plateau. Oahu is the site of Honolulu (the state capital), Pearl Harbor, and Waikiki. Other important cities are Aiea, Kailua, Kaneohe, and Wahiawa. Military installations, tourism, pineapples, and sugar are economically significant. Pop. (1990) 836,207.