Caves and Lava Tubes in Hawaii: The Complete Island-by-Island Guide

Hawaii sits on some of the most active volcanic geology on Earth, which means it also has some of the most dramatic underground landscapes. The islands are riddled with lava tubes — tunnels carved by flowing lava as the outer shell cooled and hardened while molten rock continued moving inside. The Big Island alone hosts the world's longest confirmed lava tube: Kazumura Cave, surveyed at more than 40 miles end to end. Across all four major islands, visitors can walk through lit show caves, book guided wild-caving adventures, wade into ancient sea caves, and explore a limestone cavern filled with the bones of extinct birds. This guide covers every major cave in Hawaii — which ones you can visit, how to get in, and what to know before you go.

Quick Reference: Hawaii's Major Caves

Big Island: The Lava Tube Capital of the Pacific

The Big Island is where Hawaii's volcanic geology is most active and most accessible. The same Kīlauea volcano that has been erupting for decades also built the vast network of lava tubes beneath the island's eastern and southern slopes. Three very different cave experiences are available here, ranging from a five-minute walk through a lit show cave to multi-hour expeditions into untouched passages.

Nahuku (Thurston Lava Tube) — Hawaii Volcanoes National Park

Nahuku is the most visited cave in Hawaii, and the easiest. Located inside Hawaii Volcanoes National Park about 1.5 miles past the entrance, the tube is roughly 600 feet long, lit by the National Park Service, and surrounded by a lush fern forest loop trail. The trail takes about 30 minutes total. Admission is included with your Hawaii Volcanoes National Park entry fee ($35 per vehicle as of this writing — check nps.gov for current fees). The cave was discovered in 1913 by journalist Lorrin Thurston; its official Hawaiian name, Nāhuku, means "the protuberances." Ceilings reach over 20 feet in places, and the cave floor is level and paved.

Note: Hawaii Volcanoes NP periodically closes areas due to volcanic activity, eruptions, elevated sulfur dioxide levels, or earthquake damage. Always check nps.gov/havo for current alerts before visiting.

Kazumura Cave — World's Longest Lava Tube

On the eastern slope of Kīlauea, beneath sugarcane fields and residential neighborhoods, runs one of the most extraordinary geological features on Earth. Kazumura Cave has been surveyed at approximately 40.7 miles (65.5 km) in total length and 3,614 feet deep — making it the longest and deepest lava tube in the world. It formed about 500 years ago during the ʻĀilāʻau eruption and has 101 known entrances. The cave contains lava speleothems (formations), multiple overlapping tube levels, and lavafalls where lava once cascaded from upper passages to lower ones.

Kazumura is entirely on private land and is not accessible without a licensed guide. Tour operators offer experiences ranging from short introductory walks to extended expeditions in deeper sections. Wear clothes you don't mind getting dirty. Book well in advance; tour slots fill up.

Kaumana Caves State Park — Near Hilo

A few miles west of Hilo, Kaumana Caves formed from an 1881 Mauna Loa lava flow and is one of the few cave systems in Hawaii you can explore independently and for free. A staircase descends into a fern-draped pit, then the tube branches into two passages: one heading east (toward Hilo) and one heading west. Both passages extend far into the darkness — bring a reliable flashlight or headlamp, wear closed-toe shoes with grip, and expect wet, uneven floors. The cave is open and free; parking is available. It's a reasonable stop if you're already visiting Akaka Falls or the Hilo area.

Kula Kai Caverns — Ka'ū District

On the southern tip of the Big Island, in the dry Ka'ū lava fields near South Point, Kula Kai Caverns offers guided tours through lava tube systems with formations rarely seen in the more-visited tubes near Hilo. The company runs tours ranging from a one-hour "lighted tour" (no gear required) to a two-hour "wild" spelunking experience with helmets, lights, and crawling through tighter passages. The Ka'ū district is remote — plan the drive carefully. Book through the operator's website; tours are by appointment.

Maui: Lava Tubes and Sea Caves on the Road to Hana

Ka'eleku Caverns (Hana Lava Tube)

Near the town of Hana on Maui's eastern coast, Ka'eleku Caverns is a lava tube system estimated at around 30,000 years old and stretching well over half a mile in surveyed length. The attraction offers guided tours as well as self-guided options with equipment provided. The cave interior includes lava formations and historical graffiti from 19th-century visitors. It's a reliable stop on the Road to Hana — check hours and book ahead since tour availability varies by season. Wear sturdy, closed-toe shoes.

Waianapanapa State Park Sea Caves

Waianapanapa State Park near Hana is best known for its black sand beach, but the park also contains sea caves accessible by wading through shallow coastal pools on the lava shelf. The caves are large enough to enter when the ocean is calm — you wade through ankle-to-knee-deep water to reach the cave opening, then look back at the sea framed through the entrance. A Hawaiian legend holds that the cave was a hiding place for a princess, whose presence is signaled by small red shrimp that turn the water red inside.

Access requires a state park reservation: Waianapanapa now requires all non-resident visitors to book in advance ($5 per person, $10 parking) at gostateparks.hawaii.gov. Never enter the sea caves when ocean swell is elevated — rogue waves surge into the caves without warning.

Kauai: The Limestone Exception

Makauwahi Cave Reserve

Hawaii is almost entirely volcanic, which makes Makauwahi unique: it is the largest limestone cave in the state. Located near Māhā'ulepū Beach on Kauai's south coast, the cave formed over roughly 400,000 years from hardened sand dunes. About 7,000 years ago the ceiling collapsed, creating an 80-foot-deep sinkhole now filled with freshwater and surrounded by lush vegetation. Excavations begun in 1992 uncovered nearly 10,000 years of sedimentary history, including bones of approximately 40 bird species — about half of them now extinct, including the flightless Kauaʻi mole duck and the turtle-jawed moa-nalo.

Access to Makauwahi has changed over time — the land is private property (Grove Farm). Check the Makauwahi Cave Reserve's current status before visiting, as public access has been intermittently restricted. When open, the site has operated as a free volunteer-run conservation reserve with guided tours available on certain days.

Oahu: Kaneana Cave and Its Kapu

Kaneana Cave (Makua Cave)

On Oahu's remote northwest coast near Makua Beach, Kaneana Cave is a large natural lava tube that has been sacred to Native Hawaiians for centuries. The cave is associated with Nanaue, the legendary shark man born from the union of a woman and the shark god Kamohoali'i, and is considered among the most spiritually significant natural sites on the island. The cave opening is visible from the road and large enough to walk into — but should not be entered. This is not a tourist attraction. It is a site of deep cultural and spiritual importance, and entering without permission is both disrespectful and, in the view of many practitioners of Hawaiian tradition, dangerous. Treat it as you would any sacred place: observe from a respectful distance.

When to Visit and What to Bring

Lava tubes maintain a consistent cool, humid environment year-round — inside Kaumana Caves, temperatures hover around 60–65°F regardless of the weather outside. For the Big Island caves, conditions are best in the drier months (May through September) when rain doesn't pool on cave floors as heavily. For Maui's Ka'eleku and Waianapanapa, Road to Hana access is year-round but weekday visits reduce crowds significantly.

What to bring: closed-toe shoes with traction (flip-flops and sandals are unsuitable for any cave beyond the paved Nahuku tour), a headlamp or flashlight for self-guided caves, a light jacket (caves are noticeably cooler than outside), and water. For guided wild-caving tours, the operator provides helmets and lights.

Frequently Asked Questions

What is the longest lava tube in the world?

Kazumura Cave on the Big Island of Hawaii, surveyed at approximately 40.7 miles (65.5 km) long and 3,614 feet deep. It formed during an ʻĀilāʻau lava flow about 500 years ago. Only small sections are accessible via guided commercial tours.

Can you visit lava tubes in Hawaii without a guide?

Yes — two caves are self-guided: Nahuku (Thurston) in Hawaii Volcanoes NP (lit and paved, free with park entry) and Kaumana Caves near Hilo (free, bring your own flashlight). All other significant caves require a commercial guide or have restricted access.

Are Hawaii's caves sacred?

Many are. Kaneana Cave on Oahu is the most prominent example — a deeply sacred site that should not be entered. Always research cultural status before approaching any cave and heed posted signs.

What is special about Makauwahi Cave on Kauai?

It is Hawaii's largest limestone cave — an 80-foot-deep sinkhole formed from collapsed sand dunes, containing one of the state's richest fossil records: bones of ~40 bird species, half now extinct. Check current access status before visiting as it is on private land.

Is Thurston Lava Tube open?

Nahuku (Thurston) is generally open, but Hawaii Volcanoes NP may close areas due to volcanic activity, sulfur dioxide, or earthquake damage. Check nps.gov/havo for current conditions before visiting.

What should I bring to visit a lava tube?

For Nahuku: nothing special — it's lit and paved. For Kaumana: reliable flashlight/headlamp, grip shoes, light jacket. For guided wild cave tours, the operator provides helmets and lights; wear clothes you can get dirty.

Are there sea caves in Hawaii?

Yes — Waianapanapa SP on Maui has accessible sea caves (reservation required). Na Pali Coast has dramatic sea caves viewable from boat tours. Always check ocean conditions before entering any sea cave; surge is dangerous.

How do I book a Kazumura Cave tour?

Kazumura is on private land and requires a licensed guide. Search for current operators offering Kazumura Cave tours on the Big Island and book well in advance — slots fill quickly.