Glow on, Sydney. It’s time to get your gum boots dirty and venture into the ghostly abyss of Helensburgh Glow Worm Tunnel. Unlike most of Sydney’s secret tunnels, we can’t quite call this one abandoned, as it’s home to one of New South Wales's largest colonies of bioluminescent bugs.
These semi-rare glowworms – essentially the larvae of fungus gnats (small flies) – are only found in dark and humid places across Australia and New Zealand. While most ghost hunters head to the Blue Mountains to witness this shining natural spectacle, you can also head south to these hidden tunnels just over an hour's drive from Sydney CBD.
The history of Helensburgh’s spooky underground passage dates back to the 1880s, when it was used to transport coal from the local mine to the suburbs. The tunnels were closed in 1915 due to hazardous smoke and soot build-up and were left abandoned until the mid-90s… when a colony of fragile glowworms moved in.
You’ll audibly gasp as you behold the thousands of blue-glowing bugs, sparkling like stars in vibrant shades of blue and green. Since you can’t knock before entering (the glowworms are disturbed by noise), be sure to avoid flash photography, any kind of smoke or insect repellent, and shining your torch directly at the worms. The tunnels are incredibly slippery after rain, so we’d also recommend checking the tunnels are open before visiting and entering at your own risk.