Visiting the Mermaid’s Cave in Oahu, Hawaii

Equally enchanting and controversial, Oahu’s Mermaid Cave is a hidden sea cave on the western side of the island.

After experiencing the Mermaid Cave myself, I must say — it does feel like something straight out of a mermaid movie! Light flows through openings in the cave’s ceiling, glistening on the turquoise blue water below. And best of all, there are sea turtles feeding on the rocks in the caves.

But as magical as it feels to swim inside, I can’t recommend visiting this stunning sea cave to everyone. It is challenging to get in (and out) of the cave, and can be very dangerous if you aren’t aware of the tides and your own abilities. Community members are also complaining about tourists littering and disrespecting locals here.

In this article, I’m sharing my honest thoughts about these issues, and I’m also sharing exactly what you need to know before visiting the Mermaid’s Cave.

👋🏽 Note from the author: Did this article impact the way you planned your trip? Have any questions? Please comment at the end of the article! It helps this blog grow and helps me know what types of articles to write more. 💛

A Guide to the Mermaid’s Cave in Oahu, Hawaii

A peek at what it’s like to visit Hawaii’s picturesque Mermaid Cave

What to Know Before Visiting the Mermaid’s Cave

Hawaii’s so-called Mermaid Cave is a limestone sea cave on the Oahu’s leeward (western) coast near Nānākuli Beach Park. Given the cave’s undeniable beauty and mystical name, it’s no surprise that nearly anyone who hears about it wants to find it!

However, this sea cave is not an established tourist attraction. It’s just a cave that happens to go viral on social media every once in a while. ‘Mermaid Cave’ isn’t even an official name, though I had trouble finding another name for the place (if you know the Hawaiian name, please share!)

Safety Issues

There are several reasons Oahu’s Mermaid Cave can be dangerous. There is always the possibility of:

• Being swept out to sea from inside the cave
• Getting stuck in the cave if you aren’t strong enough to pull yourself out (the only way out is by hoisting your body through a small opening in the ceiling!)
• Being bashed against the rocks when there are larger waves
• Falling through holes in the rock when searching for the cave
• Being injured when cliff jumping into the cave

With this in mind, never visit the cave alone, only visit a low tide, and only climb in if you’re 110% certain you’ll be able to get out. Check local tide charts here and be aware that swells can happen at anytime. It’s also worth reading Hawaii’s official Ocean Safety Guide!

Also Read: What to Know BEFORE Swimming with Sharks in Oahu

Cultural Issues

Since first publishing this Oahu Mermaid Cave guide in 2023, I’ve received emails and messages from several Hawaiians who live in Waianae about issues surrounding the Mermaid Caves.

As with many places that go viral, Oahu’s Mermaid Cave is not set up to support mass tourism. And unfortunately, the growing popularity of this place is putting a strain on locals who have to deal with the trash tourists leave behind.

Ocean rescues are another problem here (and in plenty of other areas in Oahu). Many people underestimate the power of the ocean and overestimate their own abilities, which leads to dangerous situations.

Hawaii’s official tourism site encourages visitors to ‘travel pono‘. In Hawaiian, pono means ‘to do what is right’. If you choose to visit the Mermaid’s Caves, do what is right and leave it better than you found it — this means not only cleaning up after yourself, but also taking any trash left by other tourists.

Respect any locals you meet. If someone advises you against going in the water, listen. Do not put yourself in unnecessary danger. It’s not just about your life (which is so very valuable!) but also about the local rescue teams that are already strained.

Is it okay to visit Oahu’s Mermaid Cave?

As of right now, it is legal to visit the Mermaid’s Cave. However, whether you should climb into the cave is dependent on your own physical abilities AND the current tide/ocean conditions. As I mentioned before, never go in the cave alone and only go in if you know that you can pull yourself out.

How to Find the Mermaid’s Cave

The Mermaid’s Cave is about 45 minutes from Waikiki on the western coast of Oahu and less than ten minutes away from Electric Beach (one of my favorite places to snorkel!)

The cave is just south of Nānākuli Beach Park, so you can follow GPS directions to the beach, but I have the cave location pinned on my free Oahu Google map.

As you approach the cave, you’ll turn left onto Pillokahi Ave and then right onto Keaulana Ave. From there, the cave is a short walk away around the corner on the limestone cliffs.

Be careful as you navigate the jagged rock, as it is very sharp, and there are large openings that can be difficult to see—you do not want to trip and fall through!

To find the main back entrance to the Mermaid Cave, walk along the back edge of the rocks until you find a two small openings with rocks and shells below. The openings are right by a fence with a “No Trespassing” sign. (Don’t worry, the caves are outside of the trespassing area.)

The pin on my map is a pretty accurate location for the entrance to the Mermaid Caves. You can use your phone to find the exact spot if you’re having any trouble finding it.

You Might Also Like: Swimming With Dolphins on the West Coast of Oahu

Parking

There are two places with free parking near the Mermaid Cave. The first is the street directly behind the caves, Keaulana Ave. My husband and I were able to easily find a parallel parking spot on this street, and the walk from the car was very short.

Alternatively, you can park in the lot at nearby Nānākuli Beach Park. From there, you’ll walk about 5-10 minutes to the limestone rock formations and caves.

Essentials to bring with you

There are a few things I highly recommend buying (or bringing) for your visit to the Mermaid Caves.

First, water shoes. These will come in handy not only while you’re swimming in the cave, but also when you’re climbing in and out. The jagged rock can be very sharp and water shoes do a great job protecting your feet from cuts.

You’ll also probably want goggles or a snorkel set, though you can certainly get by without goggles since the coolest part of the cave is the cave walls and the turquoise blue water, not what’s underwater.

A GoPro is also worth considering, given how picturesque this place is!

Also See: Hawaii Packing List

My Experience Swimming in the Oahu Mermaid Caves

I had a positive experience swimming in the Mermaid Cave. For context, my husband and I visited after high tide as the tide was going out during the month of October.

We drove all the way to west Oahu from Kailua, where we were house-sitting for a week.

We parked on Keaulana Ave and carefully walked across the rocks with our water shoes until we found the opening near the end of the cave and lowered ourselves in.

A group of people standing near the Mermaid’s Cave, which is difficult to see from above. / Climbing down into the cave can be tricky!

At the end of the cave there was a 2-3 foot beach and there was a few feet of air above the water in most parts of the cave, plus several openings.

We were able to swim through the caves safely, and when more powerful waves came, we stood up and held onto the lava rock above for stability.

We got the Mermaid Cave to ourselves for a little while, then some teenagers came and started jumping into the water through some of the openings with deeper water.

We didn’t do any cliff jumping, but we did carefully walk above the caves and peeked down into the water below. We even saw a sea turtle feeding in one of the grottos!

Also See: 4 Day Oahu Itinerary Full of Sunshine, Aloha, and Adventure

The limestone cliffs and cave entrances at near Nānākuli Beach

Is it worth visiting the Mermaid’s Cave?

Maybe. After seeing the Mermaid Cave once, I don’t know if I’ll ever go back. The cave is undeniably beautiful and being able to swim in it feels so special. However, it definitely was one of those places where you can sense the power (and danger) of nature.

If you are a confident, adventurous swimmer who understands the power of the ocean and knows how to read a tide chart, you’ll probably want to experience these stunning sea caves near Honolulu.

However, if you’re uncertain of your abilities and don’t like taking risks, I’d just skip the cave. Hawaii has so much to offer and the Mermaid Cave is a bit out of the way from other Oahu attractions (besides Electric Beach). You’re probably better off spending your time elsewhere on the island!

I have dozens of other Hawaii travel guides, including my list of 25 Oahu hidden gems. If you like to explore places off the beaten path, be sure to check it out!

Thanks for reading!

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