Mauna Kea is the tallest volcano in Hawaii: 4207m. It is 1 million years old and last erupted 4500 years ago. Mauna Kea. Mauna Kea. Mauna Kea. Mauna Kea. Weather station. Summit of Mauna Kea. Dwellings for the staff working at the telescopes installed at the top of Mauna Kea. KohalaMauna Loa Labels