This job puts you in some interesting situations, and ziplining in an underground cave is something I didn't even know existed, let alone ever thought I'd ever find myself doing.
It's pretty hard to know what to expect, but like many attractions in New Zealand it's another way to get an adrenaline hit doing something a bit left field – after all this is the country that decided it was a great idea to throw yourself off a bridge attached to a huge springy cord, or hurtle down a hill inside a large inflatable ball. When you live so far south of the rest of the world, you invent your own fun – I guess.
We arrive at Waitomo Adventures HQ a bit early, perfect timing for a coffee and some home baking. Just as we take our last sip and hoover up the remaining caramel slice, our guides arrive to take us on the 20-minute drive to the cave where our adventure will begin.
As always with these excursions, the van journey is a great opportunity to learn about the area and get relaxed in the company of the people who might see you at your worst – in this case if you get wobbly before stepping off a zipline platform into the abyss. We are fascinated to find out this is one of 300 known caves in the area; I'm sure many New Zealanders just associate Waitomo with the one tourist cave and the boat ride we all remember from childhood. It's actually a labyrinth of underground activity – from tiny nondescript holes to giant calcified cathedrals all running below farms, properties and public spaces.
One of our guides, Iain, tells us the story behind the "Lost World" cave we're heading towards. In 1906, surveyors discovered its entrance and were gobsmacked to find they were looking 90 metres down at the tops of trees, rather than the usual lichen and mosses. They described it as "a fairyland without the fairies" and it's not hard to see why.
Another hole further around provides backlighting, so rather than looking down a pitch black abyss, like normal, they found themselves peering into another glorious dimension – swirling mist, lush green foliage, clear flowing water – the stuff of Tolkien's fantasies.
Harnessed up, I'm ready to descend into this very entrance, with my crew in tow. I'd be lying if I said I wasn't slightly nervous, there's 80 metres between me and the floor and this is not like ziplining in trees or out in wide open spaces; trees are soft if you brush them – here I can see solid looking stalactites close to the trajectory. We pick our way round to the platform and I'm very glad not to have a fear of heights – curling ourselves round some tight corners with a whole lot of nothing below is not for the vertiginous, even with a harness on.
But of course it's all fine once I step off and any nerves disappear as I whoosh down the line; I really do love ziplining – as a woman in my mid-40s I'm getting a bit big for flying foxes in playgrounds and this is like the best grown-up version, without scaring small children.
Once safely grouped on the far platform, we all make our way to the next launch site. This line is a bit trickier as we need to repel around a bulbous formation that guards the entrance to the next abyss, more like a traditional caving manoeuvre. There's an incredible moment of dangling midway in silence while my probing light scours the sheer walls and makes the shadows dance – this really is unlike any ziplining experience I've ever had before, and I'm loving it.
This whole experience – called "the Lost World through the Window" – is the perfect mix of enough adrenaline to keep you on your toes, and enough stunning vistas to have you periodically wide-eyed and scrambling for words. While my heart is definitely racing, both times I step on to the platform and summon the courage to step out, fear turns to exhilaration in a matter of seconds. These guys know how to run an impressive tourist operation and even convince us all to hang off the side of the rock between the two lines, supported only by our harnesses for a picture – the kids leap straight into it, it takes me a few apprehensive attempts to release my leech-like grip.
I guess they should know what tourists like by now – Waitomo Adventures have been doing this for more than 30 years. Nick, and his wife, Carole opened the original Lost World adventure (the ziplining is only six years old) back in 1987, with an attraction that consisted of abseiling 100 metres directly down into the same cave as we're in. It's still very popular to this day and, once you hit the deck, you can opt to get out the relatively short dry way (Lost World half-day) or the much longer, wet way (Lost World all-day Epic). They also have another operation in a different cave called "Haggas Honking Holes", which Nick describes as "either Indiana Jones goes caving, or being flushed down the loo on a rope" – I think I'll leave that one to the thrill seekers.
A black water rafting operation and a troll cave for kids is also on offer, and, if you're the member of the family who doesn't like the sound of any of this, they've recently put a day spa and flotation tank at their HQ so you can have some downtime, while your family or friends do their rock jumping, waterfall sliding, abseiling, black water rafting, ziplining shenanigans. Genius.
Off the other end of the zipline, we carefully ease our way along narrow ledges and hear the roar of black water rapids far below, punctuated by squeals of delight (well, we think it was delight) as fellow adventurers get their rush on the abseiling adventure in the same cave.
Eventually, we start to glimpse small shafts of daylight as we start our ascent towards the bush line, finally leaving the mesmerising underground realm far below us. No-one can wipe the smiles off our faces as the sunlight hits our faces on a blue sky Waikato day.
I can't help but laugh at myself thinking that Waitomo was just one cave. There are endless adventures, both underground and above, all over this region – and I can't wait to come back for more.
Alexia Santamaria was a guest of Hamilton & Waikato Tourism.
Getting there: Waitomo Adventures (waitomo.co.nz) is two-and-a-half hours by car from Auckland or one hour's drive from Hamilton Airport.
Staying there: Te Tiro Accommodation (waitomocavesnz.com) is magical. Choose from simple, but cosy pioneer cottages or a gorgeous glamping tent, the views are incredible and there's even a little glowworm grotto on the property.