| 1,545 km²|
| Pearl Harbor, Diamond Head, Haiku Stairs, Hanauma Bay, Polynesian Cultural Center|
Honolulu, Waikiki, Kailua, Kapolei, Schofield Barracks
O?ahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands; however, it is home to about two-thirds of the population of the U.S. state of Hawaii, and is the home of Honolulu International Airport. The state capital, Honolulu, is on O?ahus southeast coast. Including small close-in offshore islands such as Ford Island and the islands in Kaneohe Bay and off the eastern (windward) coast, it has a total land area of 596.7 square miles (1,545.4 km2), making it the 20th largest island in the United States.
In the greatest dimension, this volcanic island is 44 miles (71 km) long and 30 miles (48 km) across. The length of the shoreline is 227 miles (365 km). The island is the result of two separate shield volcanoes: Wai?anae and Ko?olau, with a broad "valley" or saddle (the central O?ahu Plain) between them. The highest point is Kaala in the Wai?anae Range, rising to 4,003 feet (1,220 m) above sea level.
Ala Moana Beach
Ko Olina Beach Park
The 300-year-old Kingdom of O?ahu was once ruled by the most ancient Ali?i in all of the Hawaiian Islands. The first great king of O?ahu was Mailikukahi, the law maker, who was followed by many generation of monarchs. Kualii was the first of the warlike kings and so were his sons. In 1773, the throne fell upon Kahahana, the son of Elani of Ewa. In 1783 Kahekili II, King of Maui, conquered O?ahu and deposed the reigning family and then made his son Kalanikupule king of O?ahu. Kamehameha the Great would conquer in the mountain Kalanikupules force in the Battle of Nu?uanu. Kamehameha founded the Kingdom of Hawai?i with the conquest of O?ahu in 1795. Hawai?i would not be unified until the islands of Kaua?i and Ni?ihau surrendered under King Kaumualii in 1810. Kamehameha III moved his capital from Lahaina, Maui to Honolulu, O?ahu in 1845. ?Iolani Palace, built later by other members of the royal family, is still standing, and is the only royal palace on American soil.
O?ahu was apparently the first of the Hawaiian Islands sighted by the crew of HMS Resolution on January 19, 1776 during Captain James Cooks third Pacific expedition. Escorted by HMS Discovery, the expedition was surprised to find high islands this far north in the central Pacific. O?ahu was not actually visited by Europeans until February 28, 1779 when Captain Charles Clerke aboard HMS Resolution stepped ashore at Waimea Bay. Clerke had taken command of the ship after Capt. Cook was killed at Kealakekua Bay (island of Hawai?i) on February 14, and was leaving the islands for the North Pacific.
The Imperial Japanese Navy attack on Pearl Harbor, O?ahu on the morning of December 7, 1941 brought the United States into World War II. The surprise attack was aimed at the Pacific Fleet of the United States Navy and its defending Army Air Forces and Marine Air Forces. The attack damaged or destroyed twelve American warships, destroyed 188 aircraft, and resulted in the deaths of 2,335 American servicemen and 68 civilians (of those, 1,177 were the result of the destruction of the USS Arizona alone).
An earthquake, measuring 6.7 on the Richter scale, struck the island of Hawaii and the surrounding islands at 07:07:49 HST on October 15, 2006, causing an island-wide power outage and over $200 million in damage.
Today, O?ahu has become a tourism and shopping haven. Over five million visitors (mainly from the American mainland and Japan) flock there every year to enjoy the quintessential island holiday experience.