New Zealand North Island: Champagne Pools, Devil's Baths and volcanic Lakes.

We approach our Airbnb in Rotorua, New Zealand, when suddenly I notice a strange odor. Like something is burning. Uneasily, I look out the car window. Are the brakes smoking on our wonky rental car, which we picked up from a dubious shed at the Auckland airport? I glance, hopefully inconspicuously, at my boyfriend, but he just drives on as if nothing is wrong. The smell is getting worse. Now it smells rotten as well as burning. Has a weasel nested under our hood and is now roasting there?

"Wow, can you smell that?" I finally shout, nervously.

My boyfriend nods. "It's the hot springs!" he says.

I close my eyes. That's right! They always smell foul in Yellowstone too. Hydrogen sulfide. It smells almost as bad as when someone pulls a fat egg roll out of their pocket on the train. One slathered with raw onions.

After a cool week and a half on New Zealand's South Island, we have arrived on the North Island. Should we get out our winter jackets? Nonsense—New Zealand is in the southern hemisphere and everything in the north is closer to the equator and therefore more tropical. Nonetheless, we find, in addition to brightly colored thermal springs, also high mountains, and snow. And an alpine crossing that takes nine hours to traverse.

Find out how we wind up on a crater rim overlooking turquoise lakes instead of hiking the crossing, what a mud volcano is, and where the world's largest hot spring is located, in this second part of our New Zealand adventure.

"Holy shit, look!" I shout, pointing to a black-and-white picture that looks as if twenty volcanic craters are erupting at the same time. We are in the Waimangu Volcanic Valley—the youngest thermal area in the world.

On June 10, 1886, at 5:30 in the morning, the entire valley exploded—as can be seen on the monochrome photo on the information board. All life that had been in the valley was wiped out in mere seconds. A completely new ecosystem had begun, just 138 years ago.

In contrast, the Yellowstone supervolcano is really old—640,000 years old.

We hike down a slope on the trail and see several bubbling ponds, some of which are green-orange in color. I have to say that I have a soft spot for hot springs. I think it is ultra-fascinating that something containing such incredibly spectacular colors is bubbling and steaming directly under the thin crust of the earth. It's amazing, and dangerous at the same time. One of the most surreal hot springs in the world is the rainbow-colored Grand Prismatic in the US’s Yellowstone National Park. But that is only the third largest hot spring in the world. The largest is here, in the Waimangu Volcanic Valley in New Zealand. The green-black soup at the bottom of the valley spreads out like a huge, hellish lake. A mountain on the shoreline emits steam from its crevices and spikes. Fuming still, so many years after the eruption. Frying Pan Lake (or officially Waimangu Cauldron) is the name of this 400,000 square foot thermal spring.

And because “thermal springs” always sounds so much like wellness and relaxation, I need to say that the water here is acidic and 120-140°F hot. Not so fluffy.

Out next stop sounds a bit like an amusement park: Wai-O-Tapu Thermal Wonderland. I have no idea why a nature reserve is given such a silly name. In any case, there are no roller coasters here, but surreal hot springs of all colors. Some smell of oil, some are so corrosive that they eat away at the surrounding rock, some glow yellow, some form tiny sinter terraces. One particularly beautiful hot spring is called Champagne Pool. Orange on the outside, light blue on the inside. Honestly, some drunken Zeus must have come down from the sky at night and painted it all. Graffiti of the gods or something. Unbelievable!

The only thing crazier is a bright green pool, appropriately called Devil's Bath. The water itself is clear. There are residues of sulphur and minerals at the bottom that combine with the color of the water to make it look so toxic green. I wouldn't be surprised if a three-eyed great horned owl emerged from the depths, hooting out warnings to stay away.

Outside the parks, on a small side road, there is another inconspicuous, but must-see oddity—a huge mud volcano, or mud pot. A brown, mushy mass throws up bubbles at irregular intervals, which pop and collapse again as if you were whipping up chocolate pudding. But the sludge isn't boiling from heat—it's just gas rising from somewhere below the surface, making it look like someone is mixing a witch's potion in a giant caldron. I have seen similar, but smaller, features in the Mud Volcano in Yellowstone, and in Costa Rica at Rincón de la Vieja National Park.

Because this is so beautiful, I include an extra portion of photos here:

New Zealand's North Island is rife with volcanoes. Tongariro National Park has three relatively active volcanic craters—and a nine-hour trail crossing of the New Zealand Alps with fabulous views. If it's not pouring with rain.

"I booked three days here, hoping that that we can find one good day to cross the Alps!" I shout, staring angrily at the weather app. "And now it's supposed to pour rain on all three days? Come on!"

"It's the mountains," says my boyfriend, who lives in the USA among moody stone peaks.

At the same time, I discover our host has left a pile of board games and DVDs in our Airbnb, as well as information indicating that it rains here all the time. When it's not raining, it's winter and snowing. Great. Cursed mountains.

On the first day, we cannot see anything, and we are stuck in thick fog with about three inches of visibility. I don't have a clue where the alleged volcanoes could be. So, we decide to drive two hours down to the sea. The sun is shining there. That's the beauty of New Zealand—everything is so close together, and the country is small and incredibly diverse. Glaciers, volcanoes, jungle, beaches, vineyards, steppe, fjords, and redwoods—where else can you go to all these wonders in just a few hours by car? If you can afford only one long-distance trip in your life, I wholeheartedly recommend traveling to New Zealand!

 We head for Kai Iwi Beach, which is not just a beach, but cliffs, black volcanic sand—and a waterfall that crashes into the sea right on the coast. Instead of crossing the Alps on foot, I stand barefoot in the Pacific.

The next two days give us a few small, rainless windows during which we can finally do some great hikes in Tongariro National Park. We even get a quick glimpse of Mount Ngauruhoe—one of the three volcanoes—for a few minutes before it disappears again behind dark clouds. But the rest of the landscape is impressive enough. Green meadows with yellow grasses, red and black volcanic rock, a bit of blue sky (yes, really!), and white snow-capped mountain peaks. I want to throw away my passport, put a tent in my backpack, walk into the endless expanse, and never come back.

One day, we hike the Tama Lakes Trail to two lakes in two volcanic craters. "It's super stormy up there," report other hikers as they turn back. We put on our waterproof windbreakers. Ha!

After a long walk across the plains in the valley, we head up toward the crater rim. The wind is roaring, but the incredibly beautiful view keeps beckoning us forward and won't let us turn back. We scramble higher and higher over scree and rocks. Then, from the mountain saddle, we can see both volcanic lakes at the same time. Turquoise-green-blue, like diamonds shining in the dust. Behind us lies a unique, rugged, and colorful backdrop of craters and hills. I want to be able to turn my head like an owl so that I can see everything at once. A 360-degree panorama of the highest order. Wow!

Although, or perhaps because, we weren't able to hike the crossing of the Alps trail—we decide that we definitely want to come back. To Tongariro. To New Zealand.

Find more of our New Zealand adventures here:

• New Zealand South Island: Blue Fjords, red Lakes and white Nights
• Natural Wonders in New Zealand: About glowing Caves and saving the Kiwi