or Wailuku Valley
Canyon, eastern slope of Mount Puu Kukui, northwestern Maui, Hawaii, U.S. Formed by erosion, it is 5 mi (8 km) long and 4,000 ft (1,200 m) deep.
Iao Needle, a volcanic monolith 2,250 ft (686 m) high, soars nearly straight up from the valley floor.