Situated on the Reykjane peninsula in Iceland, the Krysuvik Geothermal Area consists of various geothermal fields, such as Seltun. The soil is coloured with yellow, red and green hues where solfataras, fumaroles hot springs and mud pots have formed. Explosions of overheated groundwater created several maars, or craters, near the geothermal fields, and the Gr├Žnavatn lake with its unusual green-blue colour was formed in one of the maars. In the 19th century, the area was mined for sulphur deposits.