Teapot-shaped PAUL FRANKLIN journeyed to the centre of the Earth, abseiling into the dark Waitomo caves…

If you fancy a change from New Zealand’s usual adrenalin activities, you should try the Waitomo caves.

Meaning ‘water passing through a hole’, Waitomo is just a village with a pub, campsite and a peculiar motel. In the 1800s, a bunch of waistcoat-wearing chaps went to investigate the land’s suitability for a railroad, and almost fell down a bloody great hole.

This sinkhole is about 100m deep, and is where my brother and I commenced our “Lost World Epic”. We were clad in rubber wetsuits that, if condoms, would be the opposite of fetherlite, latched to a slender cable and dropped into a mossy abyss. I’ve abseiled before, but it’s different when you aren’t leaning against a sturdy wall. You’re just dangling, easing out the rope, trying to find the balance between “too slow” and “fuck, stop!”.

The Lost World hole is aptly named, since (a) you can see how someone might lose it, and (b) it’s very Jurassic Park-like, with its prehistoric age and verdant rainforest feel.

This was the beginning, the literal scratch on the surface, of a 45km stretch of limestone caves that concede the volume of a double-decker bus each year to acid erosion.

Once at the bottom, we scrambled up some hefty boulders and stopped to make amusing silhouettes against the backlit scene of the entrance behind. My “I’m a Little Teapot” one went down well; my brother’s “Karate Kid” had been done before.

Venturing on, we saw the route we would’ve taken had it not recently rained. “Gushing” is the word. Plan B seemed preferable to drowning.

We side-stepped that via some glowworms (larvae with glow-in-the-dark poop) and braved a big ladder.

After a surprisingly arduous climb that made my forearms ache like whipping a meringue for too long, we ducked and dived and occasionally crawled until we reached a rope and a hole. We clipped on, turned around, and abseiled down a drop of unknown height whilst a gush of cold water coursed over us. You know those ‘invigorating’ shower gel adverts? Similar, minus the minty aroma.

After I’d hit the bottom, fallen on to my arse and stood up again, I got my bearings (“I’m somewhere in a dark wet hole”) and splodged to one side. Once we were all down, grinning like soggy hyenas, the guides led us through more tricky channels and to another waterfall. We were made to tuck our limbs in and turn out our headlights… then we dropped into darkness. Screaming like we were on a log flume… without the log.

Further on, past ancient whalebones and oyster fossils, we met another waterfall. But this one we were going up. We had the option of using a ladder to the side, or climb it. I did the latter, fishing for footholds through the icy spray.

The first few metres were easy enough, but near the top was an overhang, and a narrow cleft to wriggle through. The guide at the top urged me on, but I found I was hindered not only by my belt buckle snagging in the tight gap, but my right boot, filled with water, which was surprisingly heavy to lift. With one big push and a tennis player grunt, I made it. Then I crawled through a few more passages into yet another cave, flicked off my light and enjoyed a chocolate bar in total blackness.

Eventually, after a relatively gentle ascent but still flanked by some vertiginous drops, we emerged, blinking, through a small leafy hole into the daylight. My immediate thoughts were, “I could do that all over again, right now”. But, next on the agenda was a hot shower, which I happily settled for.

Once changed, we hopped back in the van to base, the sinkhole-filled field soon seeming like just any other New Zealand farm – grassy and full of sheep, with no hint as to the awesome fun that lay ‘Lost’ beneath.