Visitors explore the snow-covered summit of Mauna Kea on the Big Island of Hawaii. Mauna Kea is 13,796ft high but from from the bottom of the ocean, is the tallest mountain in the world at 33,500ft. Due to its high altitude, dry environment and isolated geographical location, Mauna Kea's summit is one of the best sites in the world for astronomical observation. Since the creation of an access road in 1964, thirteen telescopes funded by eleven countries have been constructed at the summit.