The Tongariro is a day's walk, although you can break it up with an overnight stay at a DoC hut and, as we discovered, it is doable for children.
But it's still no walk in the park, except in the literal sense. It is, in fact, a walk in New Zealand's first national park, established in 1887, when Ngati Tuwharetoa chief Te Heuheu Tukino IV gifted to the Crown 24-odd sq km, including the summits of Ngauruhoe, Tongariro and much of Ruapehu. It has been expanded over time to its present size of almost 800sq km.
The summits are still considered sacred by Maori, and Unesco has given the park world heritage status.
The crossing is a true alpine walk, says DoC's website. A challenge, say other sites. Be careful, seemed the general message; people have died on this tramp.
Although people do the trek in winter the list of must-haves (equipment such as crampons and icepicks) sounded all a little too much for us. Instead, early summer seemed a sensible time and even then we watched the weather forecast carefully.
We woke to a chilly morning at a backpackers in tiny Erua, just out of National Park Village. Unforecast low cloud blanketed the area, but our bus driver - most accommodation places offer shuttles to either end of the track - assured us it would clear as the morning went on. And it did.
Our first view of the 2287m Ngauruhoe was a hazy vertical flank, looking like a pall of darker cloud in the chilly mist. It looked awfully big and steep, even from the shuttle bus drop-off point at the Mangatepopo Valley carpark, 900m up the mountain.
The first part of the track, from Mangatepopo to Soda Springs, is a doddle. It's a well-marked track through tussock, punctuated here and there by termite-nest-like hillocks of lava. Sheer rock cliffs gash the sides of the wonderfully symmetrical Ngauruhoe on our right, like bones visible through the skin of some decomposing monster. The terrain rises gently, with boardwalks over the swampier tussock; a quick scramble over large boulders and a snow-fed mountain stream the only minor challenge. So many walkers are on the track it's like the concourse of a Westfield shopping mall. Gigantic boulders and the tumbled landscape speak of the climactic volcanic events that have taken place in this region.
The Tongariro and Ngauruhoe cones are actually one volcano, with Ngauruhoe Tongariro's main active vent. And it's been busy over the past century or two, with more than 70 ash eruptions between 1839 and 1975, when it also last spewed lava. It has been quiet lately though, its activity taken up by nearby Ruapehu.
The path to Soda Springs meanders up the valley between the two craters, a 90-minute walk that gently rises about 200m up the mountain. Then, though, the crossing takes a sudden, cruel, precipitous ascent from 1400 to 1600m; an almost vertical climb known as the Devil's Staircase.
The unstable path follows old lava flows and more recent landslips. We are grateful we followed the online advice and were wearing decent tramping boots and wondered how the woman we'd seen earlier - dressed in a lovely pair of pink Doc Marten boots - was doing. We struggled on, our lungs straining for air, panting, our lack of fitness catching up with us. Miss Eight started complaining. Were we there yet? Would we be there soon?
The Tongariro Cossing does require a reasonable level of fitness. Miss Eight ended up on her dad's shoulders, getting an even more of spectacular view of the valley rapidly receding below us. Apparently on a good day you can see Mt Taranaki from here, but today the lingering cloud hid the horizon.
It was with some relief that we reached the South Summit and took a break for a snack. The relief was shortlived.
The next stage is through the old crater, a bowl of dust surrounded by rocky slopes patched with snow. The landscape here is barren, Lord of the Rings territory. The track then climbs steeply up a ridge exposed to a cutting westerly wind. It's hand-to-hand climbing here, up loose rocks and scree.
At the top is the Red Crater, and a dizzying drop down to the Emerald Lakes on the other side.
It takes a carefully balanced run-jump gait to get down the loose scree towards the lakes, glowing in crayon-like colours from volcanic chemicals.
From there, thankfully, it's a mostly downhill zigzag walk through open tussock land. The final stretch is via lush New Zealand bush, the shade welcome after the beating sun of the tussock land.
Although an easy walk it's the longest part of the track, our minds were increasingly already focused on the chilled chardonnay awaiting us.
And there was nothing more welcome than the sight of the little white shuttle bus ready to take our tired, footsore family back to our accommodation.
TONGARIRO CROSSING
Length: 17km
Altitude: 800-1900m
Further information: See tongarirocrossing.org.nz or doc.govt.nz.
