Diamond Head dreams of a makeover

Hawaii’s most popular state park is showing its age. State officials have a grand plan to upgrade it, if only they had the money.

Diamond Head State Monument is the iconic symbol of the Aloha State. Anyone visiting the island of Oahu can’t miss it.

It’s a rite of passage in Hawaii to climb the Diamond Head Trail and take in the breathtaking views at the summit that looms over the Pacific east of the tourist Mecca of Waikiki. This point jutting out over the ocean is the southern edge of a crater, the remnants of a volcano that helped build the island and went quiet thousands of years ago.

More than 1 million people visit Diamond Head each year, following the steep trail to the summit where visitors can catch a cool Pacific breeze, a nice respite after dealing with the punishing heat and sun.

Hawaii’s state parks authorities fear more crowding and congestion to come. So they have a grand scheme to improve traffic flow, safety, and the visitor experience.

But there’s no telling when or even if their vision will ever become reality.

Dan Dennison, Communications Director at Hawaii’s Department of Land and Natural Resources (DLNR), told Public Parks that the master improvement plan now out for public comment is something that will have to wait for the unforeseeable future.

“Much later, depending on funding,” Dennison said.

Construction zone ahead, maybe

Diamond Head is on almost every packaged tour’s agenda for Oahu tourists. Its popularity has never ceased, with the exception of the war and pandemic years.

Diamond Head is accessed through a single-tunnel access point everyone vehicles and pedestrians alike take to get there, This tunnel and the parking areas nearby are increasingly congested and getting dangerous for pedestrians.

Work to enhance safety somewhat is now underway.

Hawaii’s DLNR announced last week that Diamond Head will be closed for half-days through July. Visitors can still enjoy the monument from when it opens at 6 am, but no one will be allowed in after 12:30 pm.

The closure is to accommodate construction on a “rockfall mitigation project” Dennison explained.

Other improvements DLNR would like to get done are likely several years away, the agency says.

That includes work to “improve and diversify experiences within Diamond Head crater in collaboration with local residents, visitors, community organizations, state agencies, and the general public,” DLNR says in an overview of its grand vision. 

Diamond Head is one piece of what’s left of a series of ancient volcanic eruptions that helped to build the island of Oahu, along with Punchbowl Crater and Koko Head. It’s about half a million years old, much younger than the mountains to its north.

The geological feature is known as Lēʻahi in the Hawaiian language. British sailors gave Diamond Head its English name during the 1800s.

Photo: Diamond Head as seen from Waikiki. Nathanial Gronewold, Public Parks.

Congestion has long been a problem at the single-access-point tunnel. Now, DLNR has a chance to take advantage of a golden opportunity.

Much of Diamond Head Crater is used by the State of Hawaii’s Department of Defense, home to the National Guard and Hawaii Emergency Management Agency. The State DOD now says it wants to scale back its presence there. DLNR says this could mean better public access by incorporating areas once deemed off-limits by the state DOD.

The biggest opportunity DLNR sees is to open up a second access tunnel for vehicle and foot traffic.

At present, the public can only access the Monument and trailhead by driving, biking, or walking through the Kahala Tunnel.

The tunnel was installed in the 1940s, and it’s quite narrow. Vehicle traffic is two-lane, but pedestrians must share a single-lane path that’s too small to allow for foot traffic in both directions. Instead, people must step out into the roadway and potentially into oncoming traffic to get through.

“It is not uncommon to see visitors walking onto the adjacent two-lane roadway shared by cars and commercial vehicles,” DLNR acknowledges. “The shared use of Kahala Tunnel has led to public health and safety concerns.”

Even the two-lane roadway is too narrow for larger vehicles like the ubiquitous trolley buses that traverse Waikiki and Honolulu. Larger trolleys and tour buses will navigate the tunnel by driving over the center line.

To fix these pedestrian and vehicle traffic concerns, DLNR wants to add a second tunnel to Diamond Head.

With Hawaii’s DOD scaling back its presence in Diamond Head, DLNR says it now has an opportunity to incorporate the previously off-limits Kapahulu Tunnel into the Monument’s greater infrastructure.

Kapahulu Tunnel should be reconfigured for safer pedestrian use, DLNR says. DLNR is now presenting an overview of its future management vision on the Diamond Head State Monument website.

“Under the proposed management plan, State Parks would be able to accommodate pedestrian access to the crater through the Kapahulu Tunnel,” the agency said. “State Parks is also considering opening the adjacent historic structure, Battery Harlow, to the public for interpretive access.”

The addition of the Battery Harlow area would greatly expand the area within the crater open to public use.

Currently, visitors are restricted to the road leading to and through Kahala Tunnel, a very modest visitor center with few amenities, and the Diamond Head trail itself. Adding Battery Harlow would let visitors stretch their legs a bit more, allowing them to explore more of the crater and perhaps linger a while after completing the hike to the summit.

A facelift in phases

The first part of DLNR’s plan involves improving and eventually opening Kapahulu Tunnel to pedestrians. Vehicles would continue to enter through Kahala Tunnel.

Entering the crater via the Kapahulu Tunnel will present visitors with a unique view of the crater rarely made available to the public, DLNR says.

Part two of the larger construction plan would see the introduction of an official visitor drop-off point. There, cars could temporarily unload their passengers but would then have to leave. The drop-off circle will be installed at the corner of Diamond Head Road and Makapuu Avenue.

“All pedestrian traffic would proceed through Kapahulu Tunnel, reducing the likelihood for pedestrian-vehicle conflicts,” according to this plan. This should lighten vehicle traffic inside the crater, as well.

DLNR is also planning to build an additional parking lot outside of the crater adjacent to Kapahulu Tunnel.

In the long term, DLNR says it may move all vehicle parking to points outside of Diamond Head Crater, with the exception of handicapped parking. Visitors would then either have to walk in or ride specialized golf cart-like “people movers” to get inside to the visitor center and trailhead.

However, these plans are further down the road. DLNR says at the moment it doesn’t have the money to pull the trigger on any of it.

For now, the rockfall mitigation work will have to do.

The closing of Diamond Head for half a day for the next seven months is sure to cause tour companies and tourists headaches.

As noted earlier, the site is on virtually every Oahu package tour itinerary. Tourist trollies and city buses make regular stops at the Kahala entrance point, as well. Visitors run the risk of taking a bus to the entrance in the afternoon only to have park staff turn them back.

DLNR said the current work to improve safety at Diamond Head will continue until July 2025 “or upon completion of construction.”

Given half the chance…

If they ever get the funds to implement their longer-term plans, then visitors to Hawaii will be temporarily inconvenienced again. The work DLNR says it would like to do at Diamond Head would almost certainly require lengthy road closures and restricted vehicle access. The work could also take months or even years.

But given the chance, the State Monument’s managers promise they can greatly improve access and create a better overall experience for Diamond Head’s tourists.

Visitors would be able to explore far more of the crater than they can now. The Monument’s managers are also planning to install new interpretive points to educate visitors on the history of the site, in particular the history of the many old military installations found there.

There would also be more opportunities to educate visitors on the geologic history of the ancient volcano that formed Diamond Head.

Hikers will still need sturdy shoes and plenty of water, whether their grand vision becomes reality or not.

Public Parks made the mistake of visiting Diamond Head on one of the hottest days of the year. There is little to no shade and the sun is relentless. The crater’s bottom is effectively a desert.

But those who come prepared on any day can still enjoy their adventure at Diamond Head, regardless of whether it ever actually sees any makeover, DLNR promises.

With that in mind, Diamond Head State Monument still advises everyone to “wear good walking shoes, bring water, and wear a hat and sunscreen.”