We’ve read several times that as you approach Rotorua, it’s possible to smell the town before you ever see it. Well it’s not strictly true but the pungent odour of sulphur hits us as soon as we open the car door and, as we are to discover, permeates through this most unusual city 24/7. The smell emanates, of course, from the excessive geothermal activity taking place just below ground level – the whole city of Rotorua is built over a caldera formed during a volcanic eruption around 240,000 years ago, and there is certainly no mistaking the level of activity still present today. It’s impossible to miss, in fact. But…