Topo map USGS Honolulu Mountain type Volcanic cone Designated 1968 Elevation 232 m Phone +1 808-587-0300 | Age of rock 200,000 years Easiest route Trail Address Honolulu, HI 96815, USA Prominence 182 m Parent range Hawaiian Islands | |
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Hours Open today · 6AM–6PMMonday6AM–6PMTuesday6AM–6PMWednesday6AM–6PMThursday6AM–6PMFriday6AM–6PMSaturday6AM–6PMSunday6AM–6PM Similar Tantalus, Koʻolau Range, Mauna Kea, Haleakalā, Kīlauea | ||
Diamond Head is the name of a volcanic tuff cone on the Hawaiian 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.
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Geology
Diamond Head is part of the system of cones, vents, and their associated eruption flows that are collectively known to geologists as the Honolulu Volcanic Series, eruptions from the Koʻolau Volcano that took place long after the volcano formed and had gone dormant. The Honolulu Volcanic Series is a series of volcanic eruption events that created many of Oʻahu's well-known landmarks, including Punchbowl Crater, Hanauma Bay, Koko Head, and Mānana Island in addition to Diamond Head.
Diamond Head, like the rest of the Honolulu Volcanic Series, is much younger than the main mass of the Koʻolau Mountain Range. While the Koʻolau Range is about 2.6 million years old, Diamond Head is estimated to be about 500,000 to 400,000 years old.
History
The interior and adjacent exterior areas were the home to Fort Ruger, the first United States military reservation on Hawaii. Only a National Guard facility and Hawaii State Civil Defense remain in the crater. An FAA air traffic control center was in operation from 1963 to 2001.
Tourism
Diamond Head is a defining feature of the view known to residents and tourists of Waikīkī, and also a U.S. National Natural Monument. The volcanic tuff cone is a State Monument. While part of it is closed to the public and serves as a platform for antennas used by the U.S. government, the crater's proximity to Honolulu's resort hotels and beaches makes the rest of it a popular destination.
A 0.75-mile (1.1-km) hike leads to the edge of the crater's rim. Signs at the trailhead say that the hike takes 1.5–2 hours round-trip, and recommends that hikers bring water. Although not difficult, the signs also say that the hike is not a casual one: the mostly unpaved trail winds over uneven rock, ascends 74 steps, then through a tunnel and up another steep 99 steps. Next is a small lighted tunnel to a narrow spiral staircase (43 steps) inside a coastal artillery observation platform built in 1908. From the summit above the observation platform both Waikīkī and the Pacific Ocean can be seen in detail. It is a short but steep hike – it is a 170 m (560 ft) elevation gain for a total elevation of 232 m (762 ft). There is a water fountain near the bathrooms at the foot of the trail in case you want to hydrate before the hike or fill an empty bottle. The park closes at 6:00 pm and signs posted indicate that you are not allowed to head up the trail after 4:30 pm.
National Natural Landmark
In 1968, Diamond Head was declared a National Natural Landmark. The crater, also called Diamond Head Lookout was used as a strategic military lookout in the early 1900s. Spanning over 475 acres (190 ha) (including the crater’s interior and outer slopes), it served as an effective defensive lookout because it provides panoramic views of Waikīkī and the south shore of Oahu.
The Diamond Head Lighthouse, a navigational lighthouse built in 1917 is directly adjacent to the crater's slopes. In addition, a few pillboxes are located on Diamond Head’s summit.
In popular culture
A 1975 televised game show, The Diamond Head Game was set at Diamond Head.