Trying to plan a visit to Oahu’s enchanting Mermaid Caves?
Even after exploring dozens of stunning sites on several of the Hawaiian islands over five Hawaii trips, this hidden sea cave on Oahu’s leeward side is one of my favorite places in the state.
The caves’ name, Mermaid Caves, is perfect because they really do feel like they’re straight out of a mermaid movie. Light flows through holes in the lava rock above, glistening on the turquoise blue water. And best of all, there are sea turtles feeding on the rocks in the caves!
If you’re intrigued, you’ve come to the right place. Based on firsthand experience, this Mermaid Caves Oahu travel guide will walk you through everything you need to know before visiting. This article includes details on how to find the hidden caves, essential safety tips, and pointers for sustainable and ethical travel on this part of Oahu.
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Mermaid Caves Oahu Travel Guide
What to Expect at the Mermaid Caves
The Mermaid Caves are a collection of small sea caves on Oahu’s leeward coast near Nānākuli Beach Park. With several natural openings in the lava rock, these sea caves attract daring locals and travelers who climb or jump down to explore the caves below.
Swimming in the caves is a magical experience to say the least, but it can also be dangerous and even deadly. If you do choose to get into the caves, you should be a confident swimmer, and you’ll also need to be able to pull yourself out of the cave opening.
My Experience Swimming in the Oahu Mermaid Caves
I had a wonderful experience swimming in the Mermaid Caves. My husband and I parked on the Keaulana Ave and carefully walked across the lava rock until we found the opening near the end of the cave.
We climbed down into the cave with our water shoes. When we visited, the end of the cave had a small (2-3 foot) beach that the waves, 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 Caves 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!
Another one of my favorite thrilling Oahu activities: Cliff Jumping at the China Walls
View of Nānākuli Beach Park from the volcanic cliffs where the Mermaid Caves are located
How to Get to the Mermaid Caves
The Mermaids Cave is about 45 minutes from Waikiki on the western coast of Oahu and less than ten minutes away from Electric Beach.
To get to the Mermaids Cave from Waikiki or Honolulu, follow Highway 1 (I-H-1) W out of the city. The highway will eventually become HI-93 W, and you’ll continue to follow it until you reach the edge of Nānākuli.
You’ll turn left onto Pillokahi Ave and then right onto Keaulana Ave. From there, the mermaid caves are a short walk away around the corner on the lava rock cliffs.
Be careful as you navigate the lava rock as it is very sharp, and there are large openings that can be difficult to see.
To find the main back entrance to the Mermaid Caves, 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.)
This pin on Google Maps 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
Parking for Oahu’s Mermaid Caves
There are two places with free parking near the Mermaid Caves. 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 volcanic rock formations and caves.
How to Safety Enter the Mermaid Caves
Before you try to get in the Mermaid Caves, you should ask yourself ‘will I be able to get out?’ You’ll either have to use your own strength to pull your whole body out of the small opening, get help from a friend, or climb out.
I saw another traveler who got a little panicky once she was in the cave. Thankfully, she was able to get out. I don’t think it is terribly difficult to pull yourself out, but I am a rock climber, so climbing and lifting my own body weight isn’t something unusual for me.
When we visited, there was a small (and loose!) rock on the ground below the hole that worked as a footstool. As I mentioned, it was a bit loose, so be careful, but it definitely helped with getting in and out!
Another thing to consider when entering the caves is the tide and waves. I visited right after high tide, as the tide was going out. There was a small patch of beach at the back of the cave. When the tide is lower, the beach will be bigger, meaning you can explore more of the cave on foot. You can check local tide charts here.
Be aware of how powerful the waves are, and remember that swells can happen at any time. Even if the waves are gentle when you get in, they could get bigger. Explore with caution!
What to Bring to the Mermaid Caves
There are a few things I highly recommend buying (or bringing) for your visit to the Mermaid Caves.
The main thing is 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 volcanic 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. I would personally opt for goggles by themselves because the caves are somewhat small, and breathing through a snorkel seems unnecessary. But I also always prefer my athletic goggles over snorkel gear when snorkeling. You can also totally visit the Mermaid Caves without goggles since the coolest part of the caves are the caves themselves, not what’s underwater.
A GoPro is also worth considering. The caves are breathtaking and there is no doubt you’ll want to take photos!
Also see my Complete Hawaii Packing List
Other Things to do Near the Mermaid Caves
There are variety of other things to do on Oahu’s leeward coast! Before or after visiting the Mermaid Caves, check out these other east Oahu sights:
Electric Beach: Less than ten minutes south of the Oahu Mermaids Cave, Electric Beach is one of the most unique and rewarding snorkeling spots on the island. A nearby power plant constantly releases hot water into the ocean, which attracts all types of marine wildlife. To get the full Electric Beach experience, you have to swim several hundred feet off the shore to where the pipe opening is on the ocean floor. When I visited Electric Beach, the waves were quite powerful, so I’m not sure I’d recommend this place to all people, but those who are skilled swimmer should check it out.
Nānākuli Beach Park: Just steps away from the Mermaid Caves you’ll find Nānākuli Beach, which is popular amongst locals and happens to be one of the island’s most beautiful beaches. Why not chill at this beautiful beach before or after exploring the caves.
Makua Cave Hike: Keep up the cave exploration theme and hike to a 150,000 year old cave 30 minutes north of Mermaids Cave. This is not a sea cave, but it overlooks the beautiful Pacific Ocean. Read more about this historic cave hike on University of Hawaii’s website.
Looking for more things to do on Oahu? Browse all of my Oahu travel guides.
Majestic sea turtle feeding in the Mermaid Caves
Mermaid Caves Oahu FAQs
What are the Mermaid Caves?
Oahu’s Mermaid Caves are natural sea caves in volcanic rock on the island’s western (leeward) side. These beautiful caves have become popular amongst locals and visitors alike for caving, swimming, and cliff jumping.
Where are Oahu’s Mermaid Caves?
The Mermaid Caves are located in Waianae, Hawaii, directly next to Nānākuli Beach Park on Oahu island.
Is it safe to swim in the Mermaid Caves in Hawaii?
Swimming in the Mermaid Caves can be dangerous if you’re not an experienced swimmer or are not able to pull yourself out of the caves. These natural caves are not a traditional Hawaii tourist attraction—they’re just sea caves that you can explore at your own risk. Do so with caution and care.
Is it worth visiting the Mermaid Caves even if you don’t go in the caves?
I would say yes! The caves and volcanic rock formations can easily be observed from above, and they are stunning. Just be careful as you walk since there are many holes (big and small) that you can fall through if you don’t pay attention.
Final Thoughts: Mermaid Caves Hawaii Travel Guide
Once a hidden gem, Oahu’s Mermaid Caves are becoming more popular amongst visitors. Still, it is not uncommon to be the only group in the sea caves. Never explore the caves alone and only do so if you’re confident in your swimming and climbing abilities.
Keep in mind that this part of Oahu is less visited by tourists and is mainly a residential area for local Hawaiian families. Treat the natural surroundings and people who live there with respect and care.
And of course, enjoy these stunning sea caves near Honolulu!
Essential Hawaii Resources
Traveleing to Hawaii soon? There are a lot of travel companies out there, but some are better than others. After five unforgettable trips to Hawaii, here are some of my favorite websites and resources for planning once-in-a-lifetime vacations.
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