It has taken us two years of living in New Zealand before we have managed to see some geothermal activity. Behind the thermal hot tubs at Tokaanu there is an area of geothermal springs and mud pools, which you can wander around, sticking very carefully to the path. It is a very pleasant walk with no unpleasant sulphur smells. In fact as you walk around the village of Tokaanu steam rises from pools in just about every garden. Not sure that I would like to live with the prospect of new geysers appearing in my garden.
We had a quick soak in the mineral thermal pools after the walk. An new and interesting experience. It never crossed my mind that they would actually be outside, with just a little shelter to get changed in.
The mud pool just looks like a muddy hole in the ground. Every time I turned around I heard it bubbling and just missed a snap of a mud bubble.