Waimea Canyon, Kauaʻi

Called the 'Grand Canyon of the Pacific' by Mark Twain: a gorge about 16 km long and up to 900 m deep, with red, orange and green walls and waterfalls. Waimea Canyon Drive climbs along the rim to a series of lookouts, and continues to Kōkeʻe State Park, where trails lead through cloud forest to views over the Nā Pali coast's valleys.

Go early, before clouds build up, and bring a jacket, as it's cool at the top. Kauaʻi is the oldest and greenest of the main Hawaiian islands, with no high-rises, and its scenery has appeared in films such as South Pacific and Jurassic Park. It's best explored with a rental car.