Diamond Head History
Diamond Head was originally named "Le'ahi" by the Hawaiians, which translated means "the brow of the tuna." Looking at Diamond Head from Waikiki, the profile of the crater strongly resembles the profile of a tuna (ahi) and its dorsal fin. The current name of Diamond Head came from British sailors visiting the islands in the 1800's, who climbed into the crater and found calcite deposits in the soil. Believing that the crystals were diamonds, the crater received its new name. Diamond Head crater was at one time the site for grazing livestock, but in the late 1800's the United States military began utilizing Diamond Head for its strategic advantage and built Fort Ruger within the crater's interior, the first American military installation in Hawaii. A large tunnel was dug through the crater wall to provide access to the fort, which contained a battery of cannons, a command post, and observation deck. While the fort is no longer actively used, portions of Diamond Head are still held by the military and used for training purposes.
Diamond Head Geology
Diamond Head Crater is a tuff cone, created when magma, the sea, and gases from a volcano combine to emit ash. The collection of ash hardens into tuff, which creates the conical shape. It is thought to be approximately 200,000 years old and to have gone extinct 150,000 years ago. The crater has a diameter of 3,520 feet and is fairly symmetrical, leading scientists to believe that the eruption causing the formation of Diamond Head was brief but explosive.
