Known also as the "Garden Isle", Kaua?i lies 105 miles (170 kilometers) across the Kaua‘i Channel, northwest of O?ahu. Of volcanic origin, the highest peak on this mountainous island is Kawaikini at 1,598 m (5,243 ft). The second highest peak is Mount Wai?ale?ale near the center of the island, 1,570 m (5,148 ft) above sea level.

One of the wettest spots on Earth, with an annual average rainfall of 460 inches (11,700 millimeters), is located on the east side of Mount Wai?ale?ale. The high annual rainfall has eroded deep valleys in the central mountain, carving out canyons with many scenic waterfalls.

There is no known meaning behind the name of Kaua?i. Native Hawaiian tradition indicates the name's origin in the legend of Hawai?iloa — the Polynesian navigator attributed with discovery of the Hawaiian Islands. The story relates how he named the island of Kaua?i after a favorite son; therefore a possible translation of Kaua?i is "place around the neck", meaning how a father would carry a favorite child. In South Africa, a health food and drink franchise is named after the island

During the reign of King Kamehameha, the islands of Kaua?i and Ni?ihau were the last Hawaiian Islands to join his Kingdom of Hawai?i. Their ruler, Kaumuali?i, resisted Kamehameha for years. King Kamehameha twice prepared a huge armada of ships and canoes to take the islands by force and twice failed, once due to a storm, once due to an epidemic. In the face of the threat of a further invasion; however, Kaumuali?i decided to join the kingdom without bloodshed, and became Kamehameha's vassal in 1810, ceding the island to the Kingdom of Hawai?i upon his death.

Ninini Lighthouse at Kaua?i Lagoons Golf Course, Lihu?e
View from the northern end of the Kalalau Trail overlooking Ke'e BeachThe city of Lihu?e, on the island's southeast coast, is the seat of Kaua?i County and the second largest city on the island. Kapa?a, on the "Coconut Coast" (site of an old Coconut plantation) about 6 miles north of Lihu?e, has a population of nearly 10,000, or about 50% greater than Lihu?e. Waimea, once the capital of Kaua?i on the island's southwest side, was the first place in Hawai?i visited by British explorer Captain James Cook in 1778. Waimea town is located at the mouth of the Waimea River, whose flow formed one of the most scenic canyons in the world: 3000 ft (900 m) deep Waimea Canyon. It has been called "The Grand Canyon of the Pacific."