Diamond Head, Hawaii

Diamond Head is the name of a volcanic tuff cone on the Hawaii an island of Oʻahu and known to Hawaiians as Lēʻahi, most likely from lae 'browridge, promontory' plus ʻahi 'tuna' because the shape of the ridgeline resembles the shape of a tuna's dorsal fin.Its English name was given by British sailors in the 19th century, who mistook calcite crystals on the adjacent beach for diamonds.