Diamond Head State Monument

Diamond Head State Monument is defined by its massive, circular tuff cone, a geological feature created by a single, explosive volcanic eruption approximately three hundred thousand years ago. Known to Native Hawaiians as Lēʻahi, meaning brow of the tuna, the crater sits prominently on the Honolulu skyline. Its familiar English name dates to the nineteenth century, when British sailors discovered sparkling calcite crystals on its slopes. Mistaking these worthless minerals for diamonds, they gave the landmark its enduring name.