"Yuk this SMELLS. Did someone do an eggy fart?" Matthew screwed up his nose, "it smells horrid on the moon Dad." Cameron copied his brother, wrinkling up the freckles on his nose before passing judgement, "smells yuk like Shrek." In case you were wondering, Family on a Bike haven't found a way of cycling into space; instead we were looking down into one of the most spectacular natural wonders of the Kiwi world. We were at the edge of New Zealand's famous Geyserland, built on geothermal and volcanic soil, shaped and reshaped by violent eruptions. Below us bubbled a 'Crater of the Moon'; a huge pit of stinking festering mud, while all around steam rose and hissed from the untamed grassland; from pits under the earth, from sunken holes in the floor, from the pavement underneath us. "It's a good job it's all nice and contained and they've built walkways around this stuff," I said to Stuart as the kids ran off to moan at the smell of yet another bad egg sandwich. "Imagine living in a place like this; one night out on the beers and you'd be going for a swim with Shrek in the boiling swamp." We laughed, and then cycled into Rotorua, and soon realised we hadn't seen or indeed smelt anything yet.

"Shrek would love this"

If Geyserland is a geologist's Disneyland, its' showpiece, Rotorua, is Cinderella's Palace; a neon fairyland of spa, heat and bubbles. The main tourist strip is a Vegas style festival of colour, with each motel claiming a bigger, better spa pool, spa bath, or naturally heated swimming pool. Our campsite even boasted 'hot tent sites,' a claim which we can't confirm either way as we stayed in a naturally heated cabin (with spa pool.) And for those who still can't relax, there are dozens of themed thermal centres. From Polynesian baths, to mud baths, it's all there for the dunking.

We cycled into Rotorua on one of Stuart's 'back routes', special routes that always involve travelling on gravel, mud, grass or a building site. And although much of Rotorua is manicured and attractive, this particular back route resembled Hell. First of all it smelt like nothing on earth. My sense of smell is quite pronounced right now, and every day the landscape provides a fresh assault on my nasal passages. One moment I am convinced I have just passed a field of perm lotion, the next I am virtually throwing up from the smell of asparagus soup. "Asparagus soup? I don't think the farmers have figured out how to grow that yet,' Stuart says, as I wobble on the bicycle trying to hold myself together. "Can anyone else smell curry sauce?" I ask and am greeted with only silence. An extremely distinctive malodour is a unique characteristic of Rotorua, along with the sight of hot water. From cracks in the pavement, sulphurous smoke billows and hisses. Drains bubble over with boiling water and gases, and pits of bubbling mud adorn the public parks. We crossed boiling rivers and streams to enter a traditional Maori village, where beautiful carved buildings fought to be seen amid the choking sulphurous smoke.

Go across the boiling river, past the steaming drain and into the village

The kids loved Rotorua for its' luge, its' live farm tours, and for the sheer number of swimming pools. Stuart loved it for its' scientific interest and spent days peering into pools of mud and sulphur. I managed to stand Rotorua for a couple of days, and then admitted defeat. "Please can we go somewhere nasally bland and boring?" Stuart and the kids reluctantly left the geothermal area behind, cheering up only a few days later when we were offered a beach house to stay in for free. "Look look, this house has got an elf," said Matthew as he and Cameron produced a plastic garden gnome from a cupboard they had been routing through in the back. They turned on a switch on it's back, "what does this do Mum?" Completely unprompted from the backside of the gnome came the largest fart in history. The kids thought it was hilarious and spent an entire night making the gnome trump. "Mum mum, it's Rotorua ," Matthew squealed. "We've got a farting elf and he smells worse than Rotorua. Yuk, yuk. What a great treat. Come over here Mum and he'll do one just for you."

Matthew tries to befriend the farting gnome