Nahuku Thurston Lava Tube Reopens

Sep 15, 2020 | General Information

Table of Contents
Located near the summit of Kīlauea Volcano off Crater Rim Drive, Nahuku and its lush rainforest trail have been popular features in the park. An eruption from Kīlauea 550 years ago produced vigorous streams of lava, and the long, hollow tunnel was left behind when the molten rock drained away. After another eruption of Kilauea, this one in 2018, Nahuku was closed for repairs. Now it is open and with its new lights working.

Early in 2018 Park staff installed a new electrical system with energy-efficient amber LED lights to illuminate the 400-foot-long lava tube. In addition an amber spotlight shines light on a low part of the cave ceiling. The lights are working again and will automatically turn on every day at 10 a.m., and will go out at 8 p.m. The cave will remain open overnight, but it will be pitch black inside from 8 p.m. until 10 a.m. the next day. Visitors must carry their own light source if planning to explore the lava tube in the dark, before 10 a.m. or after 8 p.m.

Lava caves like Nahuku are formed when a river of lava gradually builds solid walls and a ceiling. When the lava flow stops and the last of it passes downhill, a cave is formed. These caves can be a few feet high and only yards long or they can stretch for miles with high ceilings. There are several lava tubes you can visit around the Big Island but Nahuku is the most easily accessible and is a fantastic example of a massive lava cave.

Nahuku has a flat rock floor and a ceiling height of more than 20 feet in places. The 600-foot-long cave is a great introduction to lava tube geology. The solidified drips and waves of once-liquid lava rock clearly show the molten forces that created this cave. A tropical rainforest awaits at the far end of Nahuku. The native rainforest surrounding Nahuku is home to endemic plant, bird and insect species, like the Happyface Spider.The new lighting system has the additional benefit of inhibiting the growth of non-native plant and algae species.