Hawaii's most famous landmark, a large tuff cone which was formed by a short series of explosive eruptions some 100,000 years ago overlooks the Pacific Ocean. The name "Diamond Head" was given to the crater by British sailors in the 1800's. When they first saw the crater at a great distance, the calcite crystals in the lava rock appeared to glimmer in the sunlight. The sailors mistakenly thought there must be diamonds in the soil. Diamond Head is a crater that has been extinct for 150,000 years. The crater is 3,520 feet in diameter with a 760-foot summit. When the United States annexed Hawaii in 1898, harbor defense became a main responsibility. One of the major defense forts, Fort Ruger, occupied the Diamond Head Crater. A battery of canons was located within the crater providing complete concealment and protection from invading enemies. An observation deck was constructed at the summit in 1910 to provide target sighting and a four level underground complex was built within the walls of the crater as a command post. A 580-foot tunnel was dug through the crater wall to provide easier access to the Fort. The observation deck and underground complex is now abandoned with the advent of radar but evidence of the command post is still present along Diamond Head Trail. The trail is paved almost the entire way but can be steep in spots.

Park & Hiking Information:

Picnicking on the crater floor in a landscaped meadow; detachment from the city. Moderate family hike (bring a flashlight) with panoramic view of Honolulu; trail 0.7 mile one-way and with some hazards. Viewpoint of Kahala plain. Park gate open 6 a.m. to 6 p.m.

The Diamond Head trail takes you up the inside slopes of the crater, past and through military bunkers that were built as watchtowers during the War of the Pacific. Have a flashlight handy; toward the top of the trail hikers pass through a very dark tunnel and up a steep, then winding, staircase. Crawling out of a final bunker, you'll find a sweeping view of Waikiki and the greater Honolulu area, including some of Hawaii's most expensive private estates on the mountain's southeastern flanks. In all, there are two sets of stairs, one with 99 steps and the other, 76 steps. The hike is classified as easy to moderate in exertion but is certainly worth the breathtaking, unparalleled view of the entire west side of the island, from Waikiki to Koki Head. There are no park personnel to lead the way; just follow the hundreds of visitors who ascend Diamond Head everyday. Restrooms and water fountain are located near the parking lot; a grassy area is great for picnics although there are few trees. Diamond Head Trail is 1 ¾ miles to the rim and takes about 1 ½ hours. There is NO shade schedule an early hike. Bring water and a flashlight (for the tunnel).