The geothermal area of Krísuvík can be found on the suburbs of Reykjavik, to the southwest of Hafnarfjörður in the Reykjanes peninsula. The area is in the middle of the fissure zone on the Mid-Atlantic Ridge and is made up of several geothermal fields with steam vents and mud pools. The main sites in the area are Seltún, Hverahvammur and Hverahlíð. Around the banks of the hot springs the soil is a combination of yellow, green, and red hues, and it is a place where mud pots, hot springs, fumaroles, and solfataras have formed. The area is volatile even by normal standards in Iceland. With temperatures of 200 C (392 F) below the surface, the water is boiling when it gushes out of the earth.
Krýsuvík is one of the high temperature areas in Iceland. Visitors come here to see the hot springs, take photos, and hike. At Seltún, for example, there is a wooden pathways and hiking trails that lead up the Sveifluháls mountain to the rear. Many visitors also like to explore the fumaroles, which are accessible by a rocky uphill path. Kleifarvatn is the biggest lake in the area, but 20% of its surface has diminished since a large earthquake in 2000. There are also some smaller lakes that show signs of volcanism, such as Grænavatn which is notable for its luminous green-blue hue and was formed from a maar.
There are several maars close to the geothermal fields. These are craters that were formed when groundwater overheated and exploded. There are also a number of artificial geysers in the area where boreholes were made in the 70s. During the 18th and 19th centuries sulphur deposits were mined here. Indeed, there were some farms in the area as well until the 19th century, but were subsequently vacated. Krísuvíkurkirkja, the small chapel that stood here since its construction in 1857, was erased in a 2010 fire.