Standing like a sentinel on Waikiki Beach it was obvious that it would become both a military lookout promontory as well as a fortification for defense of the Honolulu shoreline. Though it was never used in battle Fort Ruger was constructed at its summit in 1906 and was further fortified during World War II. Much of the defensive structures have been removed in the years since but it is still actively used for training exercises for the National Guard.
Today the most popular activity on Diamond Head is hiking via a singular and serpentine cutout pathway to its summit which also includes some tunnels and huge staircases. The hike itself is probably considered a moderate one as it only takes between 45 minutes to an hour to climb and considerably less time to descend. Upon arriving at the top hikers are treated to amazing 360 degree views of large expanses of the south shore, Waikiki Beach and the Koolau range complete with definitive views of the cityscape below.
As to its well known name, Diamond Head, was named by the sailors in the days after Hawaii’s discovery by the western world when they eagerly but falsely thought they had come across diamonds embedded in its formation which in reality were actually calcite crystals.