The small Australian town of Helensburgh is home to one of the most amazing places on the planet – an abandoned railway tunnel that glows an eerie blue at night.

The Helensburgh Glow Worm Tunnel is an abandoned rail tunnel in Helensburgh, New South Wales which has become famous both for the ghost stories surrounding it and the glow worm colony that give it its iconic bioluminescent blue glow. Originally known as the Metropolitan tunnel, the 624-meter-long underground passage was inaugurated at the end of the 19th century and used to transport coal from the local mine to the suburbs. However, it closed down a couple of decades later and remained abandoned until the mid-90s, enough time for a colony of glow worms to claim it for themselves…

Photo: Nooranah Malberg/Unsplash

Opened on January 1st, 1889, the Metropolitan tunnel of Helensburgh remained in operation until 1915, when it officially closed down. Years of exposure to smoke and soot from the coal made the tunnel unsafe for the trains’ crews and passengers to pass through, so the train line was duplicated and the tunnel abandoned. One end of it was sealed off and the entire place was turned into a reservoir for mining purposes.

Over the years, the tunnel was swallowed by debris and overgrowth, and most people forgot it ever existed. It was only in 1995 that the Metropolitan Colliery decided to drain the flooded tunnel, clear up the debris in and around it and transform the site into a historical attraction. However, they had no idea that their efforts would ultimately result in a unique natural spectacle.

After its initial restoration, the old railway tunnel became the home of a colony of glow worms that has since become one of the largest in all of New South Wales. They covered the tunnel ceiling, emitting a characteristic blue light to attract prey – invertebrates like mosquitoes – at night. While this bioluminescence serves a very practical purpose, it also creates a fantastic natural light show for us humans, one that locals were quick to notice.

The tunnel eventually became known as the Helensburgh Glow Worm Tunnel, and people from all over Australia started making the journey to see the natural light show for themselves. As photos and videos shot here started going viral on platforms like Facebook and Instagram, the tunnel became an international tourist attraction.

But while the town of Helensburgh welcomed the attention, the glow worms did not. As is often the case, people cared more about the quality of their photos and videos than the tunnel’s light-sensitive inhabitants, and completely disregarded warnings not to flash lights onto the roof of the tunnel or set off flares to make photos brighter. It didn’t take long for the number of glow worms in the tunnel to start dwindling.

Fearing the premature demise of their extraordinary attraction, the Helensburgh Landcare group temporarily restricted access to the Helensburgh Glow Worm Tunnel in January of 2019 to allow the glow worms to reproduce in peace after years of abuse.

It’s unclear whether the unique glow worm tunnel is currently open or closed to visitors, as we couldn’t find any updated information on the state of this amazing attraction, but if you ever get the chance to see it in person, make sure you admire the bioluminescent spectacle quietly and if you must take photos, do so without artificial light sources.