View from Pu'u Wekiu (4205 m). Mauna Kea is a dormant shield volcano, the highest summit of Hawai'i and the highest mountain in the world when taking its submarine basis as reference. It is a sacred place for the native Hawai'ians. Due to the extremely clear skies prevailing in the summit area of Mauna Kea, several astronomic observatories are operated in this exposed place.