Diamond Head

Diamond Head is an extinct volcanic crater in Honolulu on the Hawaiian island of Oahu, rising 232 meters above sea level. The summit trail passes through several lighted tunnels and climbs steep concrete stairs to an open viewing platform overlooking the coastline and city.

The American military acquired the site in 1904 and built bunkers and observation posts along the crater rim to defend Honolulu Harbor. These installations remained operational during World War II and were later opened to the public as a hiking route.

Local residents still refer to the landmark as Leahi, a Hawaiian word evoking the tuna fish whose dorsal fin mirrors the mountain's profile. The summit once served as a platform for signal fires that alerted neighboring islands to approaching vessels.

The climb takes around 30 to 40 minutes and requires moderate fitness, as the path is steep and uneven in places. Sun protection and plenty of water are essential, since much of the route offers little shade.

Inside the crater lies a flat floor where military aircraft once landed, and concrete slabs from the former runway remain visible today. The name Diamond Head came from British sailors in the 19th century who mistook calcite crystals on the slope for diamonds.