Kīlauea is the youngest and southeastern most volcano on the Big Island of Hawai`i. Topographically Kīlauea appears as only a bulge on the southeastern flank of Mauna Loa, and so for many years Kīlauea was thought to be a mere satellite of its giant neighbor, not a separate volcano. However, research over the past few decades shows clearly that Kīlauea has its own magma-plumbing system, extending to the surface from more than 60 km deep in the earth.

In fact, the summit of Kīlauea lies on a curving line of volcanoes that includes Mauna Kea and Kohala and excludes Mauna Loa. In other words, Kīlauea is to Mauna Kea as Lo`ihi is to Mauna Loa. Hawaiians used the word Kīlauea only for the summit caldera, but earth scientists and, over time, popular usage have extended the name to include the entire volcano.

Kīlauea is the home of Pele, the Hawaiian volcano goddess. Hawaiian chants and oral traditions tell in veiled form of many eruptions fomented by an angry Pele before the first European, the missionary Rev. William Ellis, saw the summit in 1823. The caldera was the site of nearly continuous activity during the 19th century and the early part of this century. Since 1952 there have been 34 eruptions, and since January 1983 eruptive activity has been continuous along the east rift zone. All told, Kīlauea ranks among the world's most active volcanoes and may even top the list.