Helensburgh Glow Worm Tunnel: A Magical Underground Experience
Deep in the hills of Helensburgh lies a relic of the 1880s that nature has reclaimed in the most spectacular way. The old Metropolitan Tunnel, better known as the Helensburgh Glow Worm Tunnel, is no longer home to steam trains. Instead, its soot-stained ceiling is covered in thousands of tiny, bioluminescent glow worms. It's one of the most-loved spots in Hidden Gems NSW.
Find this and dozens more in Hidden Gems NSW: directions, access notes and safety tips. Printed guides include 12 months of the Explorer app free. Get the guide →
Stand in the tunnel, switch off your torch and let your eyes adjust, and the darkness turns into a subterranean galaxy. It is, without a doubt, one of the most magical hidden gems in New South Wales.
Quick Facts
- Entry: Free. Not a ticketed attraction, but it's sometimes closed for flooding or to let the glow worms recover.
- Walk: Short and flat, but extremely muddy
- Conditions: Dark, wet and slippery. Bring a torch, keep it pointed at the ground and use it sparingly.
How to Get to the Helensburgh Glow Worm Tunnel
The tunnel sits near the old Helensburgh station site in the town's residential streets. On the Earth Bound map it's shown as a general area only.
- Parking: Park considerately; this is a quiet neighbourhood, so keep noise down coming and going.
- The entrance: Look for the old station platform and the brick archway. It looks like a portal into a jungle.
- The mud: The tunnel floor is almost always wet with thick, ankle-deep mud. Wear gumboots or old sneakers you don't mind ruining.
- Check before you go: Access is looked after by Helensburgh and District Landcare. If it's closed, fenced or flooded, respect it and don't go in.
Glow Worm Etiquette (Crucial)
The glow worms at Helensburgh are Arachnocampa richardsae. They're living creatures and highly sensitive to their environment. To keep the colony alive, follow these rules:
- Don't light them up: Never shine a torch or phone light at the ceiling. It "turns off" their glow for hours and can eventually kill the colony. Keep your light pointed at the ground.
- No flash photography: This is the number one reason colonies disappear. Use a tripod and a long exposure, or your phone's night mode.
- Keep it quiet and small: Noise and smoke (including vapes) distress the worms. Visit in a small group.
- No repellent inside: Put insect repellent on before you go in, not in the tunnel.
- Don't touch: Touching the walls or the worms' silk threads destroys their feeding lines.
- Leave no trace: Take all your rubbish with you.
History of the Metropolitan Tunnel
The glow worms are the main draw, but the tunnel itself is a piece of Victorian engineering. Opened in the late 1880s, it closed to trains in 1915, reportedly because the smoke from the steam engines was suffocating passengers.
The Metropolitan Tunnel is the glow worm tunnel. Nearby is the much shorter old Helensburgh tunnel, a dramatic backdrop for industrial photography. The original "Helensburgh" station sign still stands on the platform, making it feel like a ghost town frozen in time.
Tips for Your Visit
- Damp is good, floods are not: The glow worms thrive in damp conditions, but after heavy rain the tunnel can turn into a small river. Flooding has damaged the colony before and closed the tunnel, so don't go in when it's flooded.
- The best time: The tunnel is dark even by day, but the glow worms are often easier to see at dusk or night, when your eyes are already used to low light.
- Combine your trip: You're right at the gateway to the Royal National Park. Afterwards, head down the road to Kellys Falls or Stanwell Park.
Discover more NSW secrets in Hidden Gems NSW.
Helensburgh Glow Worm Tunnel FAQs
Is the Helensburgh Glow Worm Tunnel open?
It's free and not ticketed, but it's closed from time to time for flooding or to protect the colony. Check before you go and respect any closure or fence.
Can you use a torch in the glow worm tunnel?
Yes, to see your footing, but keep it pointed at the ground and never at the ceiling. No camera flash.
What should I wear?
Gumboots or old sneakers. The floor is usually covered in thick, ankle-deep mud.
Is this the same as the Newnes Glow Worm Tunnel?
No. The Helensburgh tunnel is on the edge of Sydney near the Royal National Park; the Newnes Glow Worm Tunnel is in Wollemi National Park near Lithgow.
