After a short car drive from Martinborough township, we came to the Patuna Farm Adventures home base in a place in the backblocks called Ruakōkoputuna.
There was a quick check-in before hopping on the back of a multi-seated trailer and being towed by a 4X4 across some gnarly, dusty tracks to the start of the chasm walk.
The driver told passengers to ensure smartphones weren't left in trouser pockets because they had a habit of falling out due to the bumpy nature of the road.
After a briefing about things to watch out for, people are allowed to set off at their leisure but aware they needed to be back after three hours for pickup.
A small backpack with a two-way radio in it, by the entrance gate, is pointed out in case disaster strikes and you have to contact home base.
With eager anticipation and armed with a paper guide, people set off along an undulating native bush track, which certainly gave the legs and lungs a good workout.
The first main highlight was an enormous area of limestone jutting out of the bush that featured a naturally formed walk-through section.
It's a good chance to have a breather, soak up the views, grab a bite to eat and swig of water, and importantly, take a photograph.
After more walking, and some stunning scenery worthy of being on the silver screen, we descended towards the chasm with ropes and ladders in some places.
Quick tip: Grippy shoes are a good choice for the track and along the chasm riverbed.
Before long we found ourselves in the chasm wandering along the Ruakōkoputuna riverbed.
As we walked through this natural wonderland we marvelled at a waterfall, fossilised seashells, stalactites, and simply the ongoing beauty of the place.
The steep, green-tinged walls and sculptural form of the chasm are impressive, especially some of the last cavernous section.