We have been on water in ferries, dive boat, water taxis, sea kayak and also under the water. We have been running around land on foot, trams, trains, cars – so when there was an opportunity to go underground, why not??

The sun finally returned this morning, so the choice to spend a good portion of the day in dark spaces may seem a bit odd, but it was SO worth the time spent!

Route 6 south from Carters Beach to Hokitika really does hug the undulating contours of the coast and there are many pullover spots on the way. It’s challenging to make progress south with each turn revealing something to try a capture.

So the underground adventure begins along Route 6 at Underworld Adventures in Charleston, a former gold rush town.

This area of NZ is along the zipper line of two tectonic plates crashing into each other, with the ancient limestone seabed layer being forced up above the surrounding land mass. Add a few million years and lots of water erosion and cave chambers developed and continue to evolve.

More about the glow worms later. The tour starts with a safety briefing and we are issued climbing helmets and caving headlamps. We climb into vans for a short drive up into the hills and the drop off terminal were we meet the train for the second section of transit.

The train winds uphill through the rainforest, crosses the Nile River (seriously) and brings us to the last portion of the trek, over the swing bridge and the final hike uphill to one of the three cave entries.

And the swing bridge, visions of Indiana Jones…

And we reach the mouth of the cave. BTW, our guides have informed us there are no walkways, no paths, no handrails and no stairs in the cave route. We follow their trail along footpaths defined by ropes along the cave floor, along river beds and up rock falls. Apparently we signed the waiver…

And into the hike into the cave. We are underground for two hours and cover about 2.5 km underground, which is only a fraction of the mapped extents of the cave.

Trekking through the passages…

At points in the cave trek we are bent over double to not add new gouges to our helmets or damage the cave ceilings.

There is another, larger entry to the cave system, but it is can only be reached after an 8-hour slog through the bush to get there (so no one does it).

And then there is the waterfall!

The guides save the glow worm portion of the trek for the finale. There is an active riverbed in the cave and the ceiling of this area of the cave is where the glow worms reside. The worms cling to the cave ceiling, and have a natural bioluminescence, so when we turn off all our headlamps the ceiling ends up glowing with a constellation of green pin points of light. The worms dangle multiple strands of filament to ensnare any insects (or even other glow worm gnats) that encounter their vertical webs.

Pictures are not possible without a tripod, so a photo from a postcard will have to be a placeholder. Needless to say it was amazing to see in the pitch black of the cave!

After two hours we emerge back into the sunlight, amazed and grateful to stretch, and make the return trip back via hike, train and van to the visitors center.

That was just the first part of the day – more to follow…