The Tongariro Crossing's name was changed in 2007 to the Tongariro Alpine Crossing in a bid to dissuade tourists from attempting the day-long trek taking little more than jandals and a water bottle - only to be caught by the unpredictable weather.
This should have been a warning to me too, but after checking the MetService and seeing the weather was likely to be windy but fine, I packed only a T-shirt and shorts and threw in a jacket - just in case. Thankfully, one of the members of our group brought extra thermals.
And, after breathing in the cold mountain air, I decided to add a polyprop top and over-trousers before starting the climb into the mountains that were ominously wreathed in swirling cloud.
The 19.4km crossing track in the National Park, just southwest of Lake Taupo, crosses volcanic plains, climbs sharply up the Devil's Staircase, crosses the South Crater with Ngauruhoe (2290m) on the right and Tongariro (1968m) on the left, ascends Red Crater, then descends past the stunning Emerald Lake and Blue Lakes and zigzags down the mountain.
It has the reputation of being the best day walk in New Zealand and, as such, attracts a steady stream of tourists - most of whom are kitted out properly with tramping gear and packs.
As we set off from the Mangatepopo carpark, the cloud lifted to reveal blue sky for the gentle walk along a gravel path that travelled up the valley beside bubbling streams and old, black lava flows. Clumps of scoria rose out of hardy shrubs, tussock and patches of bright green moss and on the peaks in front of us the patchy snow looked just like cookies-and-cream icecream.
After a few kilometres we came to a sign warning those without hiking boots, thermals and emergency provisions to turn back and I realised this trek was about to get serious.
On the steep 200m ascent, known as the Devil's Staircase, the altitude put paid to the shrubs leaving only lime-green lichen clinging to the black rocks. Clouds rushed over the ridge ahead, alternately chilling me or blinding me with the glare coming off swathes of snow further up the mountain. Steps had been built into this part of the track but, even so, I had to stop often to catch my breath. That was when I first spotted the little patches of snow, hidden in the shadow of rocks, stubbornly refusing to melt.
A beautiful view awaited us at the top of the ridge. South Crater stretched in front with the snowy flanks of Tongariro on the left and the conical peak of Ngauruhoe, a vent of Tongariro, on the right.
In 1990 Tongariro National Park was recognised as a World Heritage site for its volcanic features and, three years later it was the first area to be declared a World Heritage site for the spiritual and cultural values it holds for indigenous people.
Maori legend tells how Ngatoroirangi, a tohunga and navigator of the waka Arawa, was exploring the mountainous area when he was struck down by an icy wind.
Knowing he was near death, he prayed to his sisters in his far-off homeland, Hawaiiki, to send him fire. It came to his rescue, travelling under the Pacific Ocean leaving a trail of volcanic vents wherever it surfaced from Whakaari (White Island), through Rotorua, finally exploding at Tongariro and bringing Ngatoroirangi back from the brink of death.
The mountain was accordingly named Tongariro, meaning seized by the cold south wind.
Ngatoroirangi was an ancestor of the Ngati Tuwharetoa people and, in 1887, paramount chief Te Heuheu Tukino IV gave the sacred area - 2630ha including the peaks of Ruapehu, Ngauruhoe and Tongariro - to the Government to save it from exploitation so it could be held for future generations. After another short climb we reached Red Crater, at 1886km the highest point on the crossing.
From there I could see that biting wind coming off the top of the ridgeline but was surprised to find the rocks were hot and the wind was actually steam.
The combination saw me panick for a moment. Could this be a precursor to an eruption? But the notion disappeared as quickly as it came for surely there would be a lot more warning than some steam and hot rocks.
Later I learned the Red Crater last erupted in 1926 and, although Ngauruhoe had been known to erupt at least once every nine years, the last blast was in 1975.
I stopped to watch the steam, with a whiff of sulphur, rise from one of the three Emerald Lakes, gorgeous in their turquoise colours created by minerals leached from the barren landscape, before picking up hot rocks to thaw my hands before starting to scramble down the scree.
Further on, Blue Lake lived up to its reputation for beauty, something that was emphasised by its snowy setting, but Ngatoroirangi's icy wind whipped at my jacket snapping the hood against my face as I walked along the ridge. Pushing and pulling, the wind created wrinkles on the azure lake before smoothing them out again and I was glad to be wearing that thermal top and over-trousers.
The way down was pitted with scoria but mighty Tongariro offered shelter from the wind and breathtaking views of Lake Taupo made the going much easier. We came across a DoC volunteer digging a track across a swathe of snow as, despite having rebuilt the path the day before, it had slipped again because of the melting snow and many walkers.
Further down the track levelled out and zigzagged lazily through tussock and a rainbow of shrubs. I stopped briefly to gaze back up the slope, watching the steam billowing from Ketetahi Springs about halfway up and marvelling at how lucky I was to live in such a spectacular volcanic land.
As we got closer to sea level a few ferns and flaxes appeared among the scrub. Then, suddenly, I was in the middle of podocarp bush, which offered a welcome respite from the sun and wind.
When I hadn't reached the carpark after an hour, I thought the track would never end, until I heard a car engine start up and turned the corner to find what I'd been looking for. I had learned my lesson - never again will I attempt the crossing without proper thermals or underestimate the cold south wind.