Gunnuhver is a group of vigorous pools and steam vents at Reykjanes Unesco Global Geopark – Iceland. They change with time and take on new shapes regularly.
The group partly formed after earthquakes in 1967. The name stems from a story about the vicious ghost Gunna who had caused great disturbance in the area, until a priest set a trap for her and she fell into the spring. This is supposed to have happened about 400 years ago. https://www.visitreykjanes.is/en/what-to-see-do/reykjanes-geopark/geosites/index/place/gunnuhver