Waimea Canyon is a large canyon, approximately ten miles (16 km) long and up to 3,000 feet (900 m) deep, located on the western side of Kauaʻi in the Hawaiian Islands. The canyon was formed by a deep incision of the Waimea River arising from the extreme rainfall on the island's central peak, Mount Waiʻaleʻale, among the wettest places on earth.

Nā Pali Coast State Park encompasses 6,175 acres (24.99 km2) of land and is located in the center of the rugged 16 miles (26 km) along the northwest side of Kauaʻi, the oldest inhabited Hawaiian island. The Nā Pali coast itself extends southwest starting at Keʻe Beach extending all the way to Polihale State Park. The pali (cliffs) rise as high as 4,000 feet (1,200 m) above the Pacific Ocean. The state park was formed to protect the Kalalau Valley.

The Kalalau Valley is located on the northwest side of the island of Kauaʻi in the state of Hawaiʻi. The valley is located in the Nā Pali Coast State Park and houses the beautiful Kalalau Beach. The Nā Pali Coast is very rugged and is inaccessible to automobiles. The only legal ways to access the valley are by kayak or by hiking the Kalalau Trail.

Mount Waiʻaleʻale (in Hawaiian, literally, "rippling water" or "overflowing water" and also often spelt Waialeale in English without the ʻokina), elevation 5,148 feet (1,569 m), is a shield volcano and the second highest point on the island of Kauaʻi in the Hawaiian Islands. Averaging more than 426 inches (10,800 mm) of rain a year since 1912, with a record 683 inches (17,300 mm) in 1982, its summit is considered one of the rainiest spots on earth.  The local tourist industry of Waialeale has promoted it as the wettest spot, although the 38-year average at Mawsynram, Meghalaya, India is higher at 467.4 inches (11,870 mm). Both Mawsynram and Cherrapunji in Meghalaya are recognized by the Guiness Book of World Records as having higher average rainfall. Mawsynram's rainfall is concentrated in the monsoon season, while the rain at Waiʻaleʻale is more evenly distributed through the year.

Kōkeʻe State Park is located in northwestern Kauaʻi in the Hawaiian Islands. It includes a museum at the 15 mi (24 km) marker on State Road 550, which focuses on the weather, vegetation, and bird life; a lodge which serves food and sells gifts; cabins for rent; and hiking trails. The park is just north of Waimea Canyon State Park and includes 4,345 acres (17.58 km2) of mountainous terrain.

The Alakaʻi Wilderness Preserve, popularly known as Alakaʻi Swamp, is a montane wet forest on the Hawaiian island of Kauaʻi. Although the preserve is home to alpine bogs, it is not a true swamp.  It is located on a plateau near Mount Waiʻaleʻale, one of the wettest spots on Earth.