Hawaii lava tube tours don’t show up on a typical itinerary, but the people who do them never forget the experience. You’re standing inside the literal plumbing of a volcano, a tunnel that once carried molten rock so hot it glowed orange, now cool enough to walk through with a flashlight. (For the geology of how these form, see the NPS overview of lava tubes.)

Here’s the catch for summer 2026: the Maui cave many travelers search for first, Hāna Lava Tube (Kaʻeleku Caverns), is currently closed. The operator says it is temporarily closed by the government while officials schedule an archaeological inventory survey. Booking aggregators still list it. Don’t drive out the Hāna Highway for it.

That leaves three good lava tubes, all on the Big Island, all open right now. One is paved and family-friendly. One is free and self-explore. One is a guided trip into the longest known continuous lava tube on Earth, booked by phone.

Hāna Lava Tube, also called Kaʻeleku Caverns, sits about three-quarters of the way out the Hāna Highway. For years it ran as a self-guided walk through one of the larger known lava tubes on Maui, with golf umbrellas at the entrance and a self-pay box. The operator’s own site currently states the cave is “temporarily closed by the government until further notice while they schedule an archaeological inventory survey”. There’s no published reopening date.

The reason matters if you’re a planner. Hawaiian lava tubes can hold culturally significant pre-contact sites, which is why the State Historic Preservation Division requires an archaeological inventory survey before certain uses can continue. Even when these reviews end up shorter than expected, they don’t end on a publishable timeline. Plan around it.

The practical move for a Maui trip: don’t budget a stop at Hāna Lava Tube into your Road to Hāna itinerary for now. The drive is full enough without it.

Kaumana Caves Park sits about ten minutes outside Hilo and is one of the easiest free lava tubes to reach in the state. The cave formed during the 1880–1881 Mauna Loa eruption, whose flow stalled on the outskirts of Hilo. That’s why this tube exists on the edge of a populated area instead of out in the lava fields.

Practical details:

• Cost: Free. It’s a County of Hawaiʻi park, no entrance fee.
• Time needed: 30–60 minutes if you want to actually walk in a ways. Five minutes if you just want to look down the entrance.
• What to bring: A real flashlight (not just your phone). Closed-toe shoes. Long pants help. The floor is rough lava and the walls do not forgive bare skin.
• Difficulty: The first 30–50 feet are easy. Deeper in, the floor gets uneven and the ceiling drops in places. You can go as far as your comfort allows.

What makes Kaumana feel different from the National Park tube down the road is that there’s no lighting, no railings, and no ranger. You climb down a concrete staircase, the tube branches in both directions, and once you walk past where the daylight reaches, you’re in genuine darkness. Test your light before you commit to the walk. Some travelers turn around in five minutes. Others walk a hundred yards in. Both are fine.

One safety note that’s easy to miss: the cave is wet and the floor stays slippery year-round. Hilo is one of the rainier visitor areas in the state, and that water finds its way underground. Don’t run, don’t horseplay, and don’t go in alone after a heavy rain. The site has a full attraction page with directions and what to expect: Kaumana Cave.

Nāhuku (the older English-language name is Thurston Lava Tube) is the easiest, busiest, and most family-friendly lava tube in the state. It’s inside Hawaiʻi Volcanoes National Park off Crater Rim Drive, and the walk is short, paved, and lit. You won’t get lost, and you won’t need a flashlight for the main tube. Families with strollers should expect steps at the entrance and exit, so plan to carry the stroller for a short stretch.

Practical details:

• Cost: Included with your park entrance pass ($30 per private vehicle, valid 7 days; see our fees and reservations guide for the America the Beautiful options).
• Time needed: 20–30 minutes including the rainforest walk to and from the tube entrance.
• What to bring: Closed-toe shoes (the entrance ramp is wet). A light layer, since the tube interior runs cool.
• Difficulty: Easy. The lit section is a short walk on level pavement.

The whole experience starts with a five-minute walk through ʻōhiʻa-and-hāpuʻu rainforest, drops into the tube, and exits the other side back into the same canopy. If you have a flashlight, you can continue past the lit section into the unlit second portion of the tube for about another 360 feet. Most visitors walk just the lit section. Parking is in two lots, and in our experience late morning through early afternoon are the hardest times to find a spot. Early morning is the easy time.

Important caveat: Nāhuku has been closed periodically over the past few years for rockfall assessment and stabilization. Always check current park conditions on the NPS site before you drive over. An extra five minutes saves a wasted half-hour.

Kazumura Cave is the serious option. It’s east of Hawaiʻi Volcanoes National Park, about 40 minutes from Hilo and 20 minutes from the National Park visitor center. By the numbers, it is 42.5 miles long, the longest known continuous lava tube on Earth, and 3,613 feet deep. According to the operator’s own site, Kazumura Cave Tours has been leading guided trips since 1996 under Harry Shick.

Three tours are offered, all priced in cash. From the operator’s current tour page:

• Lava Falls, $60 cash per person. Two hours, group limit six, about two-thirds of a mile. Easy to moderate. Uneven floor and a couple of ladders. This is the family-and-most-travelers option.
• Pit Room, $120 cash per person. Four hours, group limit six, two miles. Moderate to challenging. Adds two lava cascades, breakdown to clamber over, and Snake Canyon. Teenagers and up only.
• Maze, $140 cash per adult. Four to six hours, group limit four. For experienced cavers with their own vertical gear. Per the operator’s tour description, it includes a 37-foot rappel down Eureka Falls and a 30-foot rappel out. Skip this one unless you actually know what a Prusik is.

Reservations are by phone only. There’s no online booking. Call (808) 967-7208 Monday through Saturday, 8 a.m. to 6 p.m. Hawaiʻi time. The Lava Falls tour usually has slots within a week or two. The four-hour Pit Room tour benefits from at least a week of lead time. The Maze tour wants at least a week, and the related vertical-training course wants a month.

A few things to know before you call:

• Cash only. They don’t take cards.
• Long pants and closed-toe hiking shoes are required. The cave temperature stays around 65°F and drippy. A light jacket helps. No slippers, no shorts, no capris. You’ll be turned away.
• Hardhats with lights and gloves are provided.
• Children must be 11 or older for the 2-hour tour. Teenagers only for the 4-hour. No kids on the Maze tour.
• Tours run in English only. Cave preservation is the operator’s top concern, and they need every visitor to follow directions clearly.
• Photography is allowed. Anything within your flash range will turn out reasonably.
• Kazumura sits on the east rift zone but well outside any modern flow areas. Cross-check current conditions on the USGS Kīlauea page before you go.

This is the one to book if you’re already going to be in the Volcano or Hilo area and you want a real cave experience. The two-hour Lava Falls tour is the right starting point for almost everyone.

Quick guide based on what travelers actually ask:

• Traveling with young kids or grandparents and short on time: Nāhuku/Thurston inside the National Park. Paved, lit, 20 minutes.
• Want something free, don’t mind doing the work yourself: Kaumana Cave near Hilo. Bring a real flashlight.
• Want a real cave tour with a knowledgeable guide: Kazumura’s two-hour Lava Falls tour. $60 cash, by phone reservation.
• Already a caver or climber: Kazumura’s four-hour Pit Room, or the Maze if you have your own vertical gear and know how to use it.

If you’re combining a lava tube with the broader National Park visit, the natural sequence is to do Hawaiʻi Volcanoes National Park first (including Nāhuku), then exit the park east toward Volcano village or Hilo. Both Kaumana and Kazumura are on that side of the island, so any of them stacks cleanly with a park day. Trying to do all three in one day is possible but a lot.

The shared rules are the same whether you’re paying $140 at Kazumura or zero at Kaumana:

• Closed-toe shoes with grip. Hiking shoes ideal; sneakers work for Nāhuku. Lava is sharp, and most cave floors are wet.
• Long pants. Required at Kazumura, smart everywhere else. The walls do not forgive bare skin.
• A light layer. Big Island lava tubes sit in the mid-60s°F year-round and drip water on you when it rains above-ground.
• A real flashlight or headlamp for the self-explore caves (Kaumana and the unlit section of Nāhuku). A budget option like the 300-lumen rechargeable headlamps on Amazon works fine. Don’t rely on a phone. The angle is wrong and you’ll burn the battery.
• Water. No food in any of them, but water is fine.

One thing that bites visitors: cell service is unreliable on the east-rift side of the Big Island. Download offline maps or take a screenshot of directions before you leave Hilo or the park.

Don’t count on transit or rideshare for any of these stops. Rent a car unless you have a confirmed tour pickup. Kaumana is ten minutes outside Hilo town. Nāhuku is inside Hawaiʻi Volcanoes National Park, roughly 45 minutes from Hilo and two hours from Kailua-Kona. Kazumura sits between the two, off Highway 11 near the village of Kurtistown.

If you haven’t booked a rental car yet, Discount Hawaii Car Rental is the booking option I use myself. It compares the major rental brands on the island in one search, with no prepayment required on most reservations (check the specific rate terms when you book). The Big Island is a place where I’d never plan a trip without a car. Public transit doesn’t reach the lava tubes, and Uber/Lyft coverage drops off fast once you leave the resort corridors.

For travelers who want to combine a guided cave tour with other Big Island activities, the broader Big Island tour catalog on Viator covers helicopter and snorkel options that pair naturally with a Volcano-area lava-tube day.

Hāna Lava Tube on Maui is off the map for now. The Big Island still has three good options. They cover the full range from free and self-explore (Kaumana) to easy and family-friendly (Nāhuku) to serious guided trip (Kazumura). Most travelers will get the most out of pairing Nāhuku with their National Park day, then adding the two-hour Lava Falls tour at Kazumura if they want a deeper experience. The geology you’ll see is a kind of experience most mainland trips cannot match.