Out Of This World Exploring The Unknown

New Zealand’s Waitomo caves produce ‘underground stars’

The shining lights are all thanks to glowworms

Spellbound Glowworms at end of cave

The glowworms of the Waitomo caves are a species only found in New Zealand. Image by Waitomo Glowworm Cave, New Zealand

As the nights get shorter, disappointed star gazers may be heartened to know that there is another way to get their star fix—by heading underground. These alternative heavenly bodies are the glowworms of the Waitomo caves in New Zealand that create a perpetual, remarkable night sky along the ceilings of the caves. The Waitomo caves have been around for millions of years and dazzling paying visitors for more than a century. Their bioluminescent decor is courtesy of the Arachnocampa luminosa, a glowworm species only found in New Zealand. In their larval stage, these glowworms go fishing with long silk threads called “snares,” creating sticky candelabras. These drippy traps reflect and diffuse the glowworm’s native light, enhancing the starry-night effect for cave-bound sky gazers. Although there are many ways to explore the caves, a standard tour takes about 45 minutes and includes a boat ride through the particularly twinkly Glowworm Grotto. Check out this earth-bound planetarium below.


The 300 caves of the Waitomo cave system began forming 30 million years ago. Image by Waitomo Glowworm Cave, New Zealand


The name “Waitomo” comes from the Maori words “wai,” meaning water, and “tomo,” meaning hole. Image by Waitomo – Glowworm Caves


Cave conditions are closely monitored and tourist volume is determined by what is best for glowworm health. Image by Kristina D.C. Hoeppner

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Hungry glowworms actually glow brighter than ones who have just eaten. Image by James Dooley

Spellbound glowworm threads

The first guided tours of the Waitomo caves began in 1889. Image by James Dooley


The sticky silk hunting technique inspired the genus the name “Arachnocampa,” meaning “spider-worm.” Image by Waitomo – Glowworm Caves

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The standard Waitomo cave tour ends with a boat ride through the very twinkly Glowworm Grotto. Image by Rio Akasaka