Which of the Hawaiian Islands is nicknamed the "Garden Isle"?

Kauai is geologically the oldest of the main Hawaiian Islands. With an area of 562.3 square miles (1,456.4 km2), it is the fourth largest of these islands and the 21st largest island in the United States. Known also as the "Garden Isle" because of the large tropical rainforest that covers most of it's surface. Kauai lies 105 miles (169 km) across the Kauai Channel, northwest of Oahu.

The highest peak on this mountainous island is Kawaikini at 5,243 feet (1,598 m). The second highest peak is Mount Waiʻaleʻale near the center of the island, 5,148 ft (1,569 m) above sea level. One of the wettest spots on earth, with an annual average rainfall of 460 inches (1,200 cm), is located on the east side of Mount Waiʻaleʻale. The high annual rainfall has eroded deep valleys in the central mountains, carving out canyons with many scenic waterfalls. Not only does Kauai hold a record in average yearly precipitation, it also holds a record in hourly precipitation. During a storm on January 24–25, 1956, a rain gauge at Kauai’s former Kilauea Sugar Plantation recorded a record 12 in (300 mm) of precipitation in just 60 minutes.

Tourism is Kauaʻi's largest industry. In 2007, 1,271,000 people visited Kauaʻi. The two largest groups were from the continental United States (84% of all visitors) and Japan (3%). The population as of 2008 was 65,689.