Gunnuhver is a highly active geothermal area of mud pools and steam vents on the southwest part of the Reykjanes Peninsula. Named after an angry female ghost, Gudrun, whose spirit was trapped in the hot springs by a priest 400 years ago, the steamy area has an eerie atmosphere and an incredible sulphur vapor.
A unique characteristic of Gunnuhver is that the groundwater here is 100% seawater, unlike other geothermal areas on the island. The colorful minerals in the ground provide vibrant hues, but danger is very real with temperatures over 300°C (570°F) so it is important to tread lightly and stick to the trails. Iceland´s largest mud pool resides at Gunnuhver; it is 20 meters (65 ft) wide of violently boiling earth.