Nature’s own light show at Wollemi National Park

The scene is set dramatically. We pan across wide-open spaces, cavernous escarpments and deep canyons, Jurassic-like pines and otherworldly woodlands. Finally the picture zeros in on a tunnel covered in undergrowth, the remnants of a former shale mining town called Newnes.

It’s here you’ll find the mouth of a 400m-long tunnel, once part of a railway line. You’re walking in, picturing Frodo in Lord of the Rings carrying a torch and some vague feeling of heroism. But tread lightly. While long abandoned by trains, the tunnel is occupied by huge colonies of glow-in-the-dark fungus gnat larvae, aka glow worms. Once your eyes adjust to the darkness, you’ll see hundreds of blue-green tail lights, like a galaxy of twinkling smartphones, held up at a stadium gig.

The Blue Mountains region is home to a disproportionate number of these babies, mostly in caves and disused mines where the squelchy warm-to-wet ratio is just right. This tunnel is special because it’s pitch black inside, making it one of the few places in Australia where glow worms can be seen during the day.

Not-so-fun fact: there’s some prep work you should do before heading out there. As the clumsy, awkward, noisy, great apes that we are, we have the power to ruin these luminous creatures’ lives. Clearly, it’s dark, so you need a torch if you don’t want to stack it – but what you don’t want to do is point it at the glow worms. Not only will it damage their bioluminescence, it’ll also turn off their lights, rendering your visit completely pointless. Turn it off or point it at the ground once you get to the really worm-heavy bits of the tunnel.  Crane your neck back and enjoy the twinkly splendour. Finally, as with most glowing things, look but don’t touch.