For those who don't know where Rotorua is (according to Wikipedia) s a city on the southern shores of Lake Rotorua from which the city takes its name, located in the Bay of Plenty Region of New Zealand's North Island.
Rotorua is a major destination for both domestic and international tourists; the tourism industry is by far the largest industry in the district. It is known for its geothermal activity, and features geysers – notably the Pohutu Geyserr at Whakarewarewa – and hot mud pools. This thermal activity is sourced to the Rotorua Caldera, on which the town lies.
One of the first things you notice on arrival into Rotorua is the strong sulphuric smell attributable to the geo-active & volcanic nature of the region.
When we visited in 2007 hubs was fascinated by the grates which allowed steam to rise and was photographing both them and the "caution - hot" signs!