Rising 31,796 feet from the ocean floor, Mauna Kea is the tallest mountain in the world. There are many legends that surround this white-capped mountain. One such story tells of a small lake near the summit named for one of the Hawaiian snow goddesses, Waiau. The lake's water comes from the annual snowfall which makes up most of the annual precipitation. According to Hawaiian legend, the lake was originally created for another snow goddess, Poliahu, by her godfather Kane as a swimming pool. Mo'oinanea, the guardian of the pool, numbed with cold any who happened to find the lake causing them to fall into a frozen sleep.
Mauna Kea is named for its annual snow cap; its name means "White Mountain". Temperatures generally hover around freezing, and most of the annual precipitation, about 9 - 11 inches, is snow. Mauna Kea makes up much of the Big Island of Hawaii, about 23%. It has been a dormant (not active, but not extinct) volcano for 4,000 years and is currently in the capping stage. This occurs when a cap of rock forms over the top of the volcano and covers the crater. Scientists predict that Mauna Kea will erupt again. When Mauna Kea becomes active again, eruptions will likely be more explosive because of the basalt rock which forms during capping.
Mauna Kea was once the site of a glacier which covered 28 square miles. This caused its slopes to be steeper than the other shield volcanoes on the Big Island. 10,000 year old permafrost has been found 10 feet beneath its surface.
Atop the summit are many observatories. Mauna Kea's atmosphere is the clearest and most rarefied on Earth, making it an ideal location for star-gazing. Also from the summit, the island of Maui is visible.