Gunnuhver geothermal area with Reykjanesviti Lighthous in the background
 
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.                                           

Reykjanesviti lighthouse on Reykjanes peninsula is an iconic historic structure. Few buildings in Iceland—or in the world—are as imposingly located. It was Iceland’s first lighthouse, and actually, there have been two versions of lighthouses with this name.

The original one was built in 1878 but got severely damaged in a large earthquake that struck in 1887. The current version was built on safer ground in 1907 at Bæjarfell hill.