This is the entrance to the hot springs! One of the best places in the world as far as I am concerned :) The middle of the north island is a lot of dormant volcanoes and sits on a huge geothermal network. Active I might add. So there are hot springs all over the place mid island. We went and sat in the mineral baths (39C) for two hours and that was one of the cooler baths...42C was the hottest. We paid extra for a private bath...so we could go in completely naked...it was fantastic