Koko Crater Arch Trail – A Secret View of Oahu’s Rugged Coastline

Koko Crater Arch is a natural limestone arch formed by erosion near the famous Koko Head Crater. This geological formation offers breathtaking views of the ocean and is a popular spot for adventurous hikers looking to experience a unique landscape.

Hiker Standing in Koko Crater Arch

Hidden on Oahu’s southeast coastline is a rocky trail that ascends the side of the infamous Koko Crater.

No – it’s not the rail track that hundreds of people hike every day… it’s a lot better hidden and less traveled. And it takes you to one of the coolest geologic formations on Oahu.

The Koko Crater Arch Trail is a short trail that takes you to a natural stone archway that’s over 60 feet long.

The best part about the Koko Crater Arch is that it’s located in a seldom-traveled area and provides unique views of the Kaiwi Shoreline.

So put on your sun hat and fill up your water bottle, we’re gonna hike right up the Koko Crater Arch!

Koko Crater Arch Trail Details

  • Difficulty: Medium
  • Hike time: 40-60 minutes (out and back)
  • Distance: 0.6-miles out-and-back
  • Terrain: Steep, rocky, dry, hard ground
  • Elevation gain: 240 feet
  • Weather: Usually very sunny and very windy
  • Permits/Fees: None
  • Parking: Free parking at Halona Blowhole Lookout parking lot
  • Facilities/Bathrooms: None

How to Get to Koko Crater Arch Trail

The Koko Crater Arch Trail is located on Kalanianaole Highway near Halona Blowhole Lookout.

If you’re driving, then the best place to park is at the Halona Blowhole Lookout parking lot. Depending on the time that you arrive, you might have to wait a few minutes for a parking stall since the parking lot tends to get busy during the day.

There are also parking stalls on the side of the road right at the entrance to the trail, but those stalls are sometimes taken by fishermen or whale watchers.

After parking at Halona Blowhole Lookout, walk back to the highway and turn left to walk back towards town.

Walk alongside the highway for about 0.2 miles until you reach a small rocky formation that plateaus out of the ground. This is the start of the trail.

The entrance to the Koko Crater Arch Trail from Kalanianaole Highway
This rocky formation that plateaus out of the ground is the start of the Koko Crater Arch Trail.

Koko Crater Arch Trail Walkthrough

As soon as you get on the trail, you’ll be treated to views of the exterior of the crater, all the way down to the rocky ocean coastline.

This is one of the few hikes on the island where you can be so close to the ocean – while being so high up on a mountain!

As you head up the trail, you’ll notice that it’s not marked – but it’s somewhat well-defined.

You can actually see the path that leads all the way to the archway from a distance, so it’s hard to get lost.

View of Koko Crater Arch from the trail
The archway is hard to spot from the trail, but you’ll soon notice it the closer you get!

You’ll eventually get to a high point on the ridgeline where two ridges converge – from there, the trail goes in a straight shot up the side of the crater to the archway.

The terrain on the trail is steep, dry, and rocky – so we recommend wearing hiking shoes to keep your feet on the ground.

Once you get to the archway, you’ll find that it’s actually VERY steep.

Looking upwards from the base of the Koko Crater Arch
Walking on top of the arch is super dangerous and not really worth it.

Climbing over the arch is not advised – it has sheer drops on both sides. Besides, the archway doesn’t have a clear endpoint or viewpoint that you haven’t already seen.

We prefer to hang out underneath the arch – it provides shade from the blistering sun and gives you unique framing opportunities for your pictures.

View of ocean looking through the bottom of Koko Crater Arch
The Koko Crater Arch not only shields you from the sun… but you can take some of the coolest photos while you relax underneath it!

One of our favorite parts of this trail is that you’ll be treated to unique views! On one side, you’ll be able to see as far as Koko Head – which is the mountain that surrounds Hanauma Bay.

View of Koko Head from Koko Crater Arch Trail
Koko Head is the mountain way off in the distance!

Don’t Go the Wrong Way When Hiking Down!

When you’re ready to hike back down, it’s easy to go down the wrong path. This was our third time visiting the arch and we still almost went the hard way down!

There are actually two ridges that descend from the Koko Crater Arch:

  • Easy way down: The smaller, less prominent ridge is less direct but much easier to walk down.
  • Hard way down: The larger ridge is a direct route to get to and from the arch but there is a bit of rock climbing near the highway.
Aerial view of ways to get down trail from Koko Crater Arch
There are two ways to get down from the Koko Crater Arch… we recommend going the easy way down.

The “easy way down” is the same route that we went up and much more accessible from the highway. However, the easy way down is a slightly longer walk back to the Halona Blowhole Lookout but it doesn’t really matter much since it’s such a short hike anyway.

How Was the Koko Crater Arch Formed?

While we couldn’t find an official report anywhere on the internet, we did speak with local geologist Shyun Ueno regarding the formation of the Koko Crater Arch.

Shyun’s best guess is that the arch was formed by a denser/younger lava flow that was deposited over a weaker/older ash flow.

The older ash flow has since eroded away, leaving the denser lava flow overhung in the arch form that exists today.

Koko Crater Arch – Our Verdict

If you’re looking for a quick scenic hike along the Kaiwi Shoreline then the Koko Crater Arch Trail is your best bet!

While it’s not the most accessible hike, it’s very low-key and you’re not likely to find many others on the trail. In fact, most times that we’ve gone there we were the only ones on the trail.

Even though the views aren’t quite as panoramic as the Makapuu Lighthouse Trail, the location of the Koko Crater Arch provides a unique view of the coastline that not many people get to see. Plus, the geologic formation of the archway provides endless photo-taking opportunities!

Trey Lewis is an outdoor enthusiast. Whether its hiking knife-edge ridges or just fishing by the river, Trey isn't afraid to get dirty in search of the next adventure.

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