Haleakala National Park
A must for any visitor to Maui is Haleakala, the world’s largest dormant volcano (it last erupted in 1790), more than 10,000 feet above sea level. A winding road rapidly ascends past green pastureland to the moonscape summit. There are some extraordinary lookouts and trails before you get to the main visitor center, which gazes down 3,000 feet at the barren crater floor. It is said that the whole island of Manhattan could fit into this crater, with no building tops poking over the rim. On a clear day, every island but Kauai is visible from here.
Admission: Three-day passes are $10 per car. Open 24/7 year-round, weather permitting.