Diamond Head State Monument

Diamond Head Rd
Honolulu, HI 96815
(800) 464-2924

Diamond Head is a volcanic cone on the Hawaiian island of Oahu and is the most popular Hawaii State Park. Hawaiians call it Lēʻahi (brow of the tuna) in reference to the formation’s ridgeline, which resembles the tuna fish’s dorsal fin. The British soldiers who visited the area in the 19th century thought that the sparkling calcite crystals on the neighboring beach were diamonds. 

Diamond Head offers stunning views of the Pacific Ocean and Honolulu that you can hike to via a trail that takes you to the edge of the 300,000-year old crater.

An entry fee of $1 per walk-in visitor and $5 per vehicle applies. 

What is Diamond Head?

Diamond Head is part of the Ko’olau Range of volcanoes that began erupting below sea level over 2.6 million years ago. A single eruption around 300,000 years ago created the crater. 

The crater encompasses 350 acres. The crater is much larger than its rim as it was formed explosively. This type of formation is known as a tuff cone. 

Diamond Head stands at an elevation of 762 feet above sea level. When measured from the crater floor, the Diamond Head Mountain towers to 560 feet. 

Diamond Head is monogenetic, which means eruption occurs only once. The last eruption of the volcanic tuff cone was likely 150,000 to 200,000 years ago. It has remained dormant since. 

What’s the Military Significance of Diamond Head?

The U.S. government purchased the Diamond Head Crater and some of the surrounding areas in 1905, and developed around 720 acres into Fort Ruger, as a way to strengthen the country’s coast artillery defense. It was Hawaii’s first U.S. military reservation. Batteries and guns were installed on the slopes of the crater and inside it. Post World War II, the facilities were upgraded, including the addition of anti-aircraft batteries to the crater’s rim.

Today, some of these installations remain. They include Battery 407, which was originally envisioned to mount guns salvaged from the USS Arizona; Birkhimer Tunnel, a bunker style battery; a National Guard emergency operations center; and the Hawaii State Civil Defense Headquarters. 

The seven tunnels constructed into the crater’s outside slope have been used by a number of agencies. Tunnel 0 is used for communication and others (Tunnels 1 to 6) serve as storage areas. Many of the tunnels have ventilation systems. 

What is there to do at Diamond Head State Park?

There aren’t many places in the world where you can hike to the edge of a volcano. The Diamond Head Trail allows this opportunity, which culminates in panoramic views of Oahu, the famous Diamond Head Lighthouse, a United States Coast Guard facility that has been featured on a U.S. postage stamp, and the beautiful Pacific Ocean. On a clear day, you can also the nearby island of Molokai. 

Built-in 1908 as part of the army coastal artillery defense system, the trail scales the inside slope of the crater for 0.6 miles. It is a switchback trail with the mountain on one side and a railing on the other. The dirt trail was built to allow the movement of people and mules hauling material for the construction of a fire control station. In 1940, the Kahala tunnel was constructed and serves as the entrance to the crater. 

There is a rest stop at a lookout point, and then you’ll make your way through tunnels and stairs. Climb 99 steps to get to the second lookout point where you’ll find a WW II bunker. A further 54 steps from there will bring you to the crater’s summit. 

The crater rim houses a picnic area, restrooms, drinking fountains and information and historical displays. 

A number of beaches and parks are in the proximity of the volcano. 

How long does it take to hike Diamond Head?

It takes about 1.5-2 hours to hike Diamond Head (1.6 miles (2.5 km) roundtrip). 

The paved surface and handrails make your hike safe and convenient. Still, some parts of the trail comprise of uneven rock, so make sure you walk carefully and don’t lose your footing. Note that you have to walk through a narrow tunnel on your way to the summit. If you’re claustrophobic, this may feel a tad uncomfortable, but you’ll be out soon and be rewarded with majestic views!  

Also, exercise caution when ascending the 99 steps at the end of your hike. Wear good hiking shoes. And to be extra cautious, bring along a flashlight so you can watch your steps. 

When is the Best Time of Year to Visit Diamond Head?

The hottest months to visit the Diamond Head are June, June, and August, with mid-August temperatures reaching 94.4 °F (34.7 °C), making it a slow season for tourism. Spring and winter are busy tourist seasons. Fall weather is pleasant to visit the volcanic formation but rainfall and snow may play spoilsport. 

Are there Diamond Head Tours?

A tour that includes all the best attractions of Oahu, including Diamond Head can be both cost and time efficient. Sightseeing tours take care of all the arrangements for you, and you don’t have to worry about transportation and parking. 

The cost of Diamond Head tours can vary quite a bit depending on the type of experience offered and different inclusions in the tour.

You can choose from a range of Diamond Head tours, from sunset tours on electric scooters, bike tours and audio hiking tours, to guided group tours taking you to other attractions such as Waimea Waterfall and hop-on, hop-off tours covering Honolulu, Pearl Harbor and Waikiki. 

What time does Diamond Head open?

The park is open from 6 a.m. to 6 p.m. Early mornings are quieter and temperatures are cooler. The time you can enter Diamond Head is 4.30 p.m. given the amount of time it takes to complete the hike. The park is open on all days, including holidays. 

How to get to Diamond Head?

From Waikiki by Car

From the Duke Paoa Kahanamoku Statue (in Waikiki) to Diamond Head

1. Head southeast on Kalakaua Ave toward Uluniu Ave – 0.3 mi
2. Turn left onto Kapahulu Ave – 0.6 mi
3. Turn right onto Castle St – 0.3 mi
4. Turn right onto 6th Ave – 246 ft
5. Continue onto Alohea Ave – 0.6 mi
6. Turn right onto Makapuu Ave – 272 ft
7. Turn left onto Diamond Head Rd – 0.3 mi
8. Turn right – 0.3 mi
9. Continue onto Diamond Head Tunnel – 0.3 mi
10. Turn left

You can pull through the side of the crater and park your vehicle in the parking lot. A parking fee of $10 for cars/vans and $20 for minibusses apply. On a busy day with limited parking opportunities, park your vehicle on the Diamond Head Road and walk 5-10 minutes to the crater. 

By Bus

Hop on the number 23 bus on Kuhio Avenue and get down at the Diamond Head State Monument bus stop. The bus will drop you just outside the crater, so there’s about a 10-minute walk to get to the start of the trail.  Visit the Bus site for the most up-to-date fares and schedules.