Formed approximately 960 years ago as a result of molten lava spewing up from underground and flowing toward the ocean, the Hana Lava Tube is one of the most fascinating stops along the Road to Hana.
As the lava continued to flow down, the top cooled and hardened to form a crust, allowing lava to continue flowing beneath it for approximately 2 more years. When the lava drained out, a huge subterranean tunnel was formed, now the largest of its kind on Maui and the 18th largest lava tube in the world! They estimate that only about half of the cave has been discovered.
The temperature of the cave ranges between 66 and 72 degrees Fahrenheit throughout the year, and the humidity remains a constant 70%. There are no bats within the cave.
https://roadtohana.com/hana-caves.php
