In case you've never been to Rotorua, then let me enlighten you about it's smell. It totally smells like egg. Like bad egg. It's gross, and it smells terrible. Like rotten terrible egg, the kind where you wrinkle your nose when it wafts your way. The reason it smells so terrible is because Rotorua lies on a caldera, which causes a lot of thermal activity (think: mud pools and geysers). The smell comes from the sulfur which wafts out all over the place. It's so pretty but smells so very gross.
What's less gross is the hot water springs that are everywhere. Literally. You'll be driving down the road and a storm drain will be letting steam out. It's not unusual for a whole river to be boiling, the steam rising well above the river. It also means that if you can get the water to run down in the open air a bit (to cool off) and then collect it, you've got yourself a hot water pool. There are many in Rotorua, and they're pretty delightful. We stopped in many to soak. The motel we stayed in in Rotorua had it's own pipe straight to a water source underneath the property, so we had our own private little hot spring. Lush!
You do eventually get used to the smell, by the way. After a day or two you barely notice it.