It’s said that Rotorua’s boiling mud, hissing steam and spurting geysers are the handiwork of two fire demons from the spirit world. A chap called Ngatoroirangi was freezing to death on the slopes of Mount Tongariro and summoned help from his ancestral land across the sea, which the Maori call Hawaiki. His family sent the two fire demons to defrost him, but as they streaked through the seas and under the land, they had to keep coming up for air and to check their course.

Wherever they raised their fiery heads, the land was ripped apart and set ablaze for all eternity. When they reached (and saved) Ngatoroirangi at Rotorua, they must have stomped around quite a lot, because the whole area seems to be full of holes that pierce the boiling core of the earth.

This tale summons up what brings people to Rotorua: its combination of vibrant Maori culture and bizarre volcanic goings-on. Even in the suburbs, you can smell the sulphur in the air: Rotorua still smells like the birth of planet Earth.

At first glance, the town itself didn’t look exotic. Flat, low-rise streets are laid out in a grid until they hit the foreshore of Lake Rotorua with its snow-capped volcano backdrop. But the odour in the air and the columns of steam rising from drains, shrubbery and especially from the end of Hinemoa Street, reminded me that I was standing slap bang on the Pacific Ring of Fire.

It soon became apparent the most exciting geothermal hotspot in Rotorua township had been nabbed by Polynesian Spa, a hot-springs spa complex based on traditional Pacific bathing. From just NZ$12 (£4.50), you can wallow in one of the many thermal mineral pools – and as every civilisation from the ancient Egyptians onwards knows hot mineral pools are the first word in feeling tip-top. I was eager to get in.

It was well after sundown and the night air was freezing, so I was apprehensive as I swapped my padded jacket for a bikini and bath robe. The water, though, was like a freshly run bath. I gleefully abandoned the bathrobe and sank into the water. Coming straight from a volcanic spring 100m away, it has to have cold tap water added to it to stop bathers from being boiled alive. It felt pretty good to me; within minutes I was no longer a weary, stressed-out traveller, but had morphed into a languid Roman empress with an army of eunuchs fanning me with peacock feathers.

Whakawerawera Thermal Valley (aka Whaka) is one of several thermal wonderlands that surround Rotorua, and also incorporates a traditional Maori village and arts and crafts centre. This was how the average Maori village looked before Europeans came along – ornately carved meeting-houses, storerooms on stilts, waka (canoe) sheds, stake fences and houses, spotting scary monster carvings, patterned beams and rich wall coverings. I scurried off down a path that led to Pohutu Geyser, away from civilisation and into an open valley from which dozens of variously sized columns of that familiar white steam rose.

I hadn’t gotten far before I saw my first mud pool. A soft, plopping sound emanated from what looked like the world’s biggest cow pat, and I could make out tiny ‘ploplets’ squirting lazily from the centre of a cauldron of smooth, hot mud. When it’s not in its scaldingly hot and bottomless state, this mud is actually good for you, as the gift shops full of Rotorua mud face masks and body scrubs suggest.

The oozing chocolate sauce lake was nothing. Mere metres further along the path, a giant 20ft-high jet of water spewed from the top of a frilly pink-and-white heap that seemed to be made of dripping candlewax, a hot, turquoise stream running around its base. Sunlight broke through billowing clouds of steam, boiling water squirting and leaping to an improbable altitude from the bowels of the earth. I’ve been to some pretty bizarre places in my time, but this was the first time I’d seen an entire green valley populated by ghost-like pillars of steam.

I’d already had a vivid introduction to traditional Maori life at Whaka, but things got even more cultural that night. Tamaki is a Maori cultural experience set in a replica pa (hill fort), reached from town by coach. Soon we were standing, waiting, under the starlit sky before a huge, forbidding stake fence, lit only by flickering torches. Before long, a wail went up from within, becoming a mesmerising, rhythmic chant.

A Maori in full warrior garb shot out of the gate and waved his spear at us, stamping, rolling his eyes, poking his tongue and glaring, as the unseen villagers backed his yelling with a te wero (challenge) song. To laugh is a major cultural faux pas, but I don’t think any of us could’ve if we’d tried. Our tribal chiefs stepped forward and did the hongi (rubbed noses) with the warrior to announce that we came in peace. The scary part over, we were invited into the pa for an evening of Maori performance and a slap-up hangi, the traditional Maori feast cooked in earth ovens dug into the ground.

Swarming in through narrow, roofless corridors, we soon emerged into the marae (village) at the centre of the pa, where tribal Maori were standing around bonfires and in front of thatched huts, chanting, dancing and practising their warrior skills. A show for the tourists, true, but still nothing short of awesome. Inside the wharenui (meeting house), the villagers performed traditional songs, stories and dances before treating us to a hangi.

Maori culture meets hot, bubbling mud and spurting geysers – the heady combination that makes Rotorua unique. It was too soon that I was heading out of Rotorua, rumbling through the now-familiar green hills with their steamy plumes of vapour. I couldn’t help but wonder if those ancient fire demons were still down there somewhere, sleeping it off and exhaling through the cracks. I don’t think you’d want to wake them.