Mauna Kea: The World's Widest & Tallest Mountain - Facts & Information

Mauna Kea is a dormant volcano on the island of Hawaii. It is the tallest mountain in the world when measured from its base on the ocean floor. Mauna Kea is 10,203 meters (33,474 ft) high from its base, while Mount Everest is 8,848 meters (29,029 ft) above sea level. Mauna Kea is also the widest mountain in the world, with a circumference of about 119 kilometers (74 miles).