Fern Grotto
Hawaii, from $35
A skylight into a long lava tube on the edge of Hilo. A very steep stairway leads down into two openings; bring a flashlight to go further in.
The story
The tube was formed by an 1881 Mauna Loa flow. According to local accounts, the lava stopped short of Hilo after Princess Ruth camped in front of it and asked the goddess Pele to spare the town. The caves closed after a rockfall in September 2023 and reopened in January 2024.
History source: .
Getting around underground
- The walk
- A very steep set of stairs into the cave. The county recommends flashlights, sturdy shoes, gloves, hard hats and long sleeves.
Good to know
- On site
- restrooms
Getting there
Kaumana Caves is in or near Hilo, HI.
Parking: The lot is across the road on a blind curve; cross carefully.
Directions in Google MapsDistances are straight-line from each city center.
Listed in: lava tubes
Checked on 2026-10-23 against hawaii-guide.com and Hawaiʻi Public Radio (January 2024 reopening). Prices and hours change, so confirm on the official site before you drive out.