National park, eastern Maui, Hawaii, U.S. Established in 1960, it occupies an area of 28,655 acres (11,597 hectares). Its central feature is Haleakala Crater, the world's largest dormant volcanic crater, more than 2,500 ft (762 m) deep and about 20 mi (32 km) in circumference. The crater floor, covering more than 19 sq mi (49 sq km), has areas of forest, desert, and meadow. It is the site of Science City, a research-observatory complex operated by the U.S. Department of Defense and the Universities of Hawaii and Michigan.
Learn more about Haleakala National Park with a free trial on Britannica.com.