Honolulu means "sheltered bay" in Hawaiian. The only natural harbour of the Hawaiian Archipelago, it was created by the Nu'uanu Stream, which carried fresh water to this area and thus prevented coral from forming in the bay. Within a mere two centuries, Honolulu developed from a relatively deserted moor to the present-day metropolis that attracts scores of tourists. Huts were replaced with skyscrapers and Hawaiians were superseded by an international population consisting of immigrants from all over the Americas, Asia and Europe. Today, the greater Honolulu area has a population of 400,000 and stretches 40km from west to east.
The island of O'ahu was formed some 3 to 3.5 million years ago following the eruption of two shield volcanoes. The archipelago's third largest island, O'ahu is actually the most important one in many respects. Representing only 10% of Hawaii's land, the island is nonetheless home to some 900,000 people-nearly 75% of the state's total population.
O'ahu's diverse geology and history have led to the development of an island with two distinct identities. Honolulu and Waikiki, on one side, are extensively developed cosmopolitan tourist areas. The backcountry, on the other side, with its papaya and coconut trees, carved cliffs and pristine beaches, boasts a timeless charm. In winter, violent storms that form in the north Pacific often unleash their wrath here, and in some places waves swell up as high as small buildings-a surfer's paradise.