I'm mesmerised, can't take my eyes off the emerald-coloured pools below. My viewing perch on this high ridgeline is seriously outside my comfort zone, but the view is spectacular and I momentarily forget everything else as I gaze at these natural wonders - the Emerald Lakes below and the imposing Red Crater beside us. No wonder the Tongariro Alpine Crossing is billed as New Zealand's best one-day walk, attracting up to 80,000 people every year.
The crossing has become even more interesting since last year's eruption of the Upper Te Maari Crater on the northern side of Mt Tongariro. The protective area designated by the rahui of the area's kaitiaki, Ngati Hikairo, in August covers a 1km radius around the vent of Te Maari.
We have full access to the track, despite the dangers of being within the Te Maari Volcanic Hazard Zone. We're told what to do if we hear any volcanic rumbles (look up and avoid flying rocks as we evacuate).
We're well aware of the impact of that activity as we witness craters that were formed by falling rocks and debris during the eruption.
The hole in the Ketetahi hut roof caused by airborne volcanic material makes us thankful no one was inside at the time. Though our guide, Catherine Wallace, a veteran of 300 crossings, finds this section more interesting now there are some new rocks to see, she appreciates how the volcanic activity reminds us all of the force of nature.
We've opted to do the crossing as a guided walk with Adrift Guided Outdoors Adventures. Along the way, Catherine shares information about the track and "our great outdoor playground", as well as giving helpful hiking advice (suggesting we swing our arms to warm our cold hands, for example). Most importantly, she shows me the safest way to negotiate the hard parts.
We're doing this alpine weekend break in style, staying at the Chateau Tongariro Hotel. When Catherine collects us, she ensures we're well-equipped for the walk. Our American companions, Laura and Adam, are loaned hiking boots, we're loaned gloves, and Catherine's backpack is crammed with first-aid gear, water and other essentials.
The 19.4km adventure is a must-do on Kiwis' and international visitors' lists. Lord of the Rings fans Laura and Adam know Mt Ngauruhoe better as Mt Doom and keep their eyes peeled for scenery they recognise from the movie.
We start off wandering through the Mangatepopo Valley, following the stream around the edge of an old lava flow and onward to Soda Springs. At Devil's Staircase, Catherine slows us to tortoise speed as we climb from 1440m to 1600m above sea level. Mist hugs Mt Ngauruhoe as we travel over layers of ancient and modern lava flows. We feel as if we're walking on the moon. I'd seen photos of this, but it's so much better in real life!
Then we reach the short, steep climb to an exposed ridge beside the Red Crater. This is where having a guide is invaluable. Catherine senses my silent fear and leads me safely along the rock face. As the others gather on the edge to look into the crater, I sneak a peek from a safe distance, and appreciate those beautiful Emerald Lakes as I summon courage for the descent (my incentive: the warm bath and three-course meal waiting for me at the Chateau).
The descent from the crater to the lakes is on loose scoria. Catherine shows us how to keep our knees bent and walk heel first to dig into the scoria and resist sliding too much. It makes it so easy, enjoyable even, and soon we're down and lakeside.
A geological type from Canterbury University who is guiding visiting American students offers congratulations: "You've just done the worst part", while Catherine high-fives me. Yeehah!
We have lunch (sandwiches have never tasted so good) then continue around the Central Crater, climbing to the Blue Lake. We catch sight of Te Maari still letting off steam and spot the new rocks.
From here, it's mainly downhill past Ketetahi Springs, through tussock, low bush and forest to our destination, the Ketetahi carpark. We've done it. We've hiked the Tongariro Crossing!
• Adrift Guided Outdoors Adventures picks up walkers from and returns them to the Chateau Tongariro Hotel and Taupo. In winter, families can do the guided Tongariro Crossing using ice picks and crampons (walkers are shown how to put on the gear and use it), which is a whole lot of fun, says guide Catherine Wallace. Adrift also offers special winter deal for families.
• A soak in Taupo's DeBretts thermal hot pools is just the thing after a day conquering the Crossing.
• Remember to add on a day for skiing on Mt Ruapehu's Whakapapa or Turoa ski fields.
• For more information, visit greatlaketaupo.com.
• Donna McIntyre was a guest in the safe hands of Adrift Guided Outdoor Adventures and enjoyed two luxurious nights at the Chateau Tongariro Hotel.