Its volcanic furnaces give the Big Island of Hawaii some of the most remarkable geologic spectacles in the world. Those spectacles aren’t limited to what we see at the surface in the form of massive shield-volcano domes, the Halemauu lava lakes, black-rock headlands. There’s some remarkable stuff underground as well, and Kazumura Cave is a spectacular example. Kazumura Cave Tours give you a rare guided look at this longest and deepest known lava tube on Planet Earth.
Lava tubes form within active lava flows, which, over time, have been in no short supply on the Big Island. As the roughly 2165-degree-Fahrenheit lava tongues its way along, it’s cooled by the air and the ground, forming an outer crust that hardens over. Insulated within, though, the flow has a molten heart that keeps flowing—sometimes for a long time. Once the inner active channel of lava drains away, you’re left with a long, linear void inside a hardened shell.
The Kazumura Lava Tube, surveyed to nearly 43 miles long, lies within a pahoehoe basalt flow of Kilauea Volcano’s Ailaau eruption from between 300 and 500 years ago. The cave’s flow runs northeast off the Kilauea flanks, and may have reached Kaloli Point on the coast. At more than 3,600 feet deep, the lava tube is also the deepest known cave in the U.S. In sections, its portal is nearly 70 feet wide and 60 feet high.
Hidden by dense windward vegetation as well as development on the surface, Kazumura Cave has at least 10 known entrances. In 1996, having explored the cave access on his property, Harry Shick began offering public tours. He’s a leading expert at this point, passionate about the Kazumura’s geology and its protection. He’s even penned a book on lava tubes and lava caves.
His Kazumura Cave Tours only explore a small portion of this vast subterranean system, but show off some spectacular features. These include dangling lavacicles, lava straws, and the extraordinary sculpted plunges known as lava falls.
There are three tour options appealing to visitors with different physical capabilities, interests, and timetables. All begin with a walk through lush rainforest to a ladder dropping into the dark lava-tube underworld. You’ll want hiking boots (or at least sturdy hiking shoes) as well as long pants for your exploration. Flashlights, hard hats, and gloves are provided.
The two-hour Lava Falls Tour, considered easy to moderate, covers two-thirds of a mile and provides a broadly appealing introduction to the cave.
The four-hour, two-mile Pit Room exploration is a bit tougher, involving some clambering over jumbled cave breakdowns. It takes visitors to a great collapsed sink within the cave.
Then there’s the Maze Tour, which is suitable only for experienced cavers. It’s four- to six-hour rope-assisted foray explores such amazing realms as Eureka and Red Column falls and the epic Sexton Maze.
Kids 11 and up can do the Lava Falls Tour, while the Pit Room and Maze tours are better for older teenagers.
All of the tours feature Harry’s enthusiastic explanation of the Kazumura Cave’s geology and natural history. He shares some great and meaty information, and his care for this place comes through clearly.
Kazumura Cave Tours puts great emphasis on low-impact cave stewardship, which is important: Parts of Kazumura Cave in the past have suffered from trash dumping and other insults. Introducing people to the wonders of this mighty lava tube is one way to help protect it. Don’t touch anything in the cave—its features can be surprisingly fragile—and don’t bring food, which can introduce bacteria and fungus that may threaten cave life.
You’ll learn a great deal on any of these three tours, and see a corner of Hawaii that few visitors even know about.
Bring along a rain jacket or windbreaker for your Kazumura Cave tour. The temperature within hovers around the mid-60s, and there’s quite a bit of dripping in the passageways.