Oahu () (Hawaiian: Oʻahu (pronounced [oˈʔɐhu])), also known as "The Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—about two-thirds of the population of the U.S. state of Hawaii. The island lies within Honolulu County and the state capital, Honolulu, is on Oahu's southeast coast.
Including small associated islands such as Ford Island plus those in Kāneʻohe Bay and off the eastern (windward) coast, its area is 596.7 square miles (1,545.4 km2), making it the 20th-largest island in the United States.Oahu is 44 miles (71 km) long and 30 miles (48 km) across. Its shoreline is 227 miles (365 km) long. The island is composed of two separate shield volcanoes: the Waiʻanae and Koʻolau Ranges, with a broad valley or saddle (the central Oahu Plain) between them. The highest point is Kaʻala in the Waiʻanae Range, rising to 4,003 feet (1,220 m) above sea level.