11 Weirdest Activities You Can Do In Hawaii – Most Visitors Fly Home Without Trying A Single One

Hawaii will hand you a free coconut and mail it anywhere in America. That’s not even the strangest thing on this list. After 30 years living on Oahu, and more neighbor island trips than I can count, I’ve learned the weird stuff is what people remember forever.

I’m not a tour guide. I’m the local friend you wish you had.

Eleven strange activities coming up, and #11 is the one locals won’t even joke about.

Float in Black Water While Giant Manta Rays Fly at Your Face

Start with the big one.

The manta ray night snorkel in Kona is the strangest 45 minutes in the whole state, and it costs about $118 to $140.

You hold onto a light board in the ocean after sunset. Plankton swarms to the lights. Then mantas with 12-foot wingspans barrel-roll inches under your belly, mouths open like garage doors.

My first time, off Keauhou at the spot dive shops call Manta Village, I counted five of them. Five. The person next to me screamed through her snorkel and it came out as a kazoo. Nobody laughed. We were all busy making the same noise.

You’re in the water 30 to 45 minutes of a two-hour trip. Take the wetsuit they offer. Take it even if you feel tough. You’re not tough at 8 pm in February.

Pro tip 🌊 – Book the earliest slot. The mantas don’t care, but the ride back gets choppy later, and cold plus chop ruins the memory.

Here’s my controversial take. This beats the dolphin swims the state basically shut down, and that shutdown should’ve happened sooner. The mantas show up by choice. That difference matters more than people admit.

And if a 12-foot animal isn’t strange enough, wait until you hear what a post office does.

The Best $15 Souvenir in America Is a Coconut With Your Name on It

On Molokai, the tiny Hoolehua Post Office runs Post-A-Nut. You grab a free coconut from a bin. You decorate it at the counter with free markers. Then you slap postage on the bare husk and mail it. No box. No wrapping. The coconut IS the package.

The program started in 1991, and the office ships around 3,000 coconuts a year.

Postage runs about $13 to $20 to the mainland, depending on how fat your coconut is.

I mailed one to my brother in Vegas with a shaka drawn on it and “wish you were here, brah” in red Sharpie. Nine days later it landed on his desk. It’s still there.

Getting to Molokai is half the fun. Mokulele’s little prop planes hop over from Maui and Oahu, low enough to spot whales in winter. The coconut sails through the mail with zero drama, by the way. Your suitcase on the flight home is the risky one – there’s a table at the airport where USDA agents quietly empty tourists’ bags of things they packed without a second thought, and a few of them will genuinely surprise you.

Molokai has no traffic lights and no buildings taller than a coconut tree. The island next door is even stranger, for a furrier reason.

The Hawaiian Island That Answers to 700 Cats

Lānaʻi has about 3,000 human residents. The Lānaʻi Cat Sanctuary alone holds more than 700 cats.

Read that math again. One cat for every four people.

It’s a four-acre open-air compound in a red-dirt pineapple field. Admission is free, donations welcome, open 9 am to 3 pm, no reservations. You walk in and cats just… arrive. On your lap. On your shoulders. One orange guy fell asleep on my slipper and I stood there 20 minutes like a hostage.

The weird part has a serious core. The sanctuary exists to protect endangered native birds. Every cat inside is one less cat hunting nēnē and ʻuaʻu chicks. You’re petting cats AND saving birds. Most Hawaii solution ever.

Day-trip over on the ferry from Maui. Half my boat last time was going only for the cats. The other half found out mid-crossing and changed their plans on the spot.

From fluffy to brutal now, because the next one makes you earn it.

The Beach With Green Sand and a Scam Waiting in the Parking Lot

There are only a handful of green sand beaches on Earth. Papakōlea, near South Point on the Big Island, is one. The sand is crushed olivine crystal from a collapsed volcanic cone. In afternoon light it glows like a broken 7-Up bottle. It smells like salt and hot grass. The wind never stops.

Getting there is a 2.5-mile hike each way.

No shade. Bring water, real shoes, sunscreen.

Now the part most blogs whisper. Guys with pickup trucks sell rides down for $20. Those shuttles are illegal. The road crosses Hawaiian Home Lands, the landowner bans vehicles, and every rental contract on the island bans that road too. Each trip tears a new scar into the coast.

We have a saying here – “if can, can. If no can, no can.” If you can’t hike it, let the beach win. And whatever you do, leave the sand there. Everyone wants a jar of that green glitter, and it sits in the same family as the lava rocks people keep mailing back to Hawaii with apology letters – there’s a whole list of cursed objects you should never take home from Hawaii, and the stories behind those returned packages get stranger the more of them you hear.

The volcano that made that green sand has a big sister. She’s been showing off.

Watch the Volcano Throw Lava Higher Than the Eiffel Tower

Kīlauea spent 2025 doing something almost nobody alive has seen. Since December 2024 it’s erupted in repeating episodes, dozens of them, with fountains that topped 1,000 feet.

Episode 27, in June 2025, threw lava higher than the Eiffel Tower.

Plumes hit 20,000 feet.

You watch from inside Hawaiʻi Volcanoes National Park, from Kīlauea Overlook, Wahinekapu, or Keanakākoʻi, a half-mile walk from parking and the closest you can get. Go at night. The crater glows orange, the steam hisses, the air smells faintly of sulfur and rain. Everyone around you goes quiet without agreeing to.

Here’s the smart play. Book a crater-view room at Volcano House, the only hotel inside the park, and check the glow from your bed instead of paying $400 for a helicopter seat.

Park entry is $30 per vehicle and it’s good for a whole week.

A helicopter turns Pele into a screensaver. The rim at night, on ground that trembles a little, beats any window seat.

One warning. The eruption pauses between episodes, sometimes for weeks. Check the USGS update the morning you go, not your hotel lobby’s brochure.

If glowing rock is too calm for you, the ocean has something with teeth.

Float in a Cage While Sharks Decide You’re Boring

Boats leave Haleʻiwa Harbor on Oahu’s North Shore before most people finish coffee. Three miles out, the water turns that deep open-ocean blue, and Galapagos and sandbar sharks show up within minutes. You climb into a floating cage with big clear windows. Around $120 to $150 per person, more for the cage-free swims with safety divers.

The strange part isn’t fear. It’s the calm.

Sharks move like they have nowhere to be. The cage rocks. Your breathing gets loud in the snorkel. Ten minutes in, you stop being scared and start feeling small. That feeling is worth every penny.

The sharks were out there the whole time, of course, three miles offshore or three hundred yards. After 30 years here, what’s actually in the water at the beaches you’ll swim at still surprised me when I dug into it, and it’s not what the movies trained you to fear.

There’s real local debate about these tours, and I’ll give it to you straight. Some fishermen and some Native Hawaiian practitioners don’t love boats conditioning sharks to engines, because manō are ʻaumākua, ancestral guardians, to many families. Others argue the tours turned thousands of tourists into shark defenders. I lean toward the second camp. I hold my breath a little writing that.

Back on the calm side of the island, a piece of land plays hide and seek.

Stand on an Island That Won’t Exist by Dinner

In the middle of Kāneʻohe Bay sits Ahu o Laka, the sandbar. At low tide, a football field of white sand rises out of turquoise water. Volleyball nets go up. Someone always has a cooler and a ukulele. Then the tide returns and the whole island vanishes like it was never there.

You reach it only by boat or kayak from Heʻeia Kea Harbor. The name means “altar of Laka,” tied to the deity of hula, so act like a guest. No glass. Pack out everything. Skip the rock stacking for your feed.

My neighbor proposed out there at low tide. He timed it so the water rose around their ankles right after she said yes. Sinking island, rising marriage. Twenty years now.

Insider tip 🛶 – Weekday mornings on a new moon give the lowest tides and the fewest boats. By 11 am on a weekend it’s a floating parking lot.

Now for the one that makes grown adults giggle.

Yes There Is a Real Mermaid School and Adults Love It

Companies on four islands strap a fabric tail and monofin on you and teach you the dolphin kick. On Maui, Hawaii Mermaid Adventures runs about $149 per person for groups. Kauaʻi sessions run around $249 with photos. In Honolulu it happens at Magic Island lagoon, minimum age 6.

I watched a 64-year-old retired firefighter from Ohio try this in Kīhei. Terrible for 20 minutes. Tangled, splashing, snorting water. Then something clicked, and he glided 15 feet underwater with a huge grin bubbling out of his face. His wife cried a little. So did the instructor, who blamed sunscreen.

Is it silly? Completely. That’s the point. You came 2,500 miles. Be silly. And if the trip budget is groaning by now, most of the real savings happen before you ever leave home – there are 15 moves that quietly save visitors the most money and hassle, and the expensive mistakes cluster in the first 48 hours.

If you’d rather be weird with 40,000 other people, clear one Saturday in April.

Eat Spam in the Street With 40,000 Strangers

The Waikīkī Spam Jam shuts down Kalākaua Avenue every spring – April 26 in 2025 – and pulls over 40,000 people for one canned meat. Spam musubi. Spam fried rice. Spam mac and cheese. I ate Spam ice cream there once. We’ve made peace.

Mainlanders joke about Spam. We don’t.

Hawaii eats around seven million cans a year, a habit born from WWII rations that became genuine comfort food.

Teri-glazed Spam on hot rice, wrapped in nori, still warm from the 7-Eleven counter, is a 10 out of 10 breakfast and I’m not taking questions. Even McDonald’s here serves Spam, eggs, and rice before 10:30 am, off a secret local menu that exists nowhere else on Earth, and what locals actually order off it says more about us than any luau.

Entry to Spam Jam is free, there’s live hula, and proceeds feed the Hawaii Foodbank. Come hungry. Leave grateful.

Then look up, because the sky here is strange too.

The Stars Look Better at 9,200 Feet Than at the Summit

The Maunakea Visitor Information Station sits at 9,200 feet, open 9 am to 9 pm every day of the year, free. On a clear night the Milky Way looks spilled. The air is thin, dry, and cold enough to see your breath in July. The VIS runs free reservation-only telescope nights most months.

Here’s the twist nobody expects. The stars look better here than at the 13,796-foot summit. Up top, mild oxygen deprivation dims your night vision. Your own eyes betray you. Lower wins. Science says so, and my frozen okole agrees.

The summit also closes 30 minutes after sunset, requires 4WD that your rental contract probably forbids, and sits on ground many Native Hawaiians hold sacred, which the telescope protests made loudly clear. You lose nothing by staying at the VIS. Bring every warm layer you packed, and stop 30 minutes to acclimatize before going any higher.

There’s one more kind of darkness on this list. Number 11. The one I saved on purpose.

Walk the Paths of the Night Marchers if You Dare

Downtown Honolulu after dark hides the old trails of the huakaʻi pō, the night marchers – processions of warrior spirits generations of local families swear they’ve heard. Drums first. Torches second. And you never, ever look.

Lopaka Kapanui, a Native Hawaiian storyteller, runs 90-minute walking tours through downtown and Waikīkī, and USA Today readers voted it the #1 ghost tour in the country three years running through 2025. No jump scares. Just history – Pakaka heiau, the buildings stacked on top of it, the security guards who quit specific posts and won’t say why.

I grew up with these stories. My grandmother put ti leaves at our door and never explained it twice. You don’t have to believe. Just notice that every local on the tour walks a little closer to the group by the end.

Where to Sleep Between the Weird Stuff

Keeping this short, since the activities are the trip. Three bases, all on Expedia:

• Kona for the mantas and green sand – Outrigger Kona Resort & Spa sits on the cliff above Manta Village, and some nights you can watch the dive lights from the lawn
• North Shore Oahu for the sharks – Courtyard Oahu North Shore in Lāʻie
• Volcano Village for lava nights – Volcano House, covered above, plus cheaper cottages in the village

Which Weird Thing Comes First

Do the manta dive if you pick only one. Do the coconut for the best $15 souvenir in America. Do the cats if your heart needs it, and hike, don’t ride, to the green sand.

The postcard Hawaii is fine. But the Hawaii that mails coconuts, schools mermaids, and throws a street party for canned meat? That’s the one that actually lives here.

Which one made you stop scrolling? That’s your answer. Book it before you talk yourself back into the luau. 🤙