volcanic landscape of leirhnjukur, myvatn geothermal area in iceland, with turquoise sulfurous lakes

area blue boiling caldera cloud crack crater crevasse field fissure formation fumarole gas geology geothermal hot spring hverarapara hverir iceland icelandic lake land landscape leirhnjukur mineral mountain mud pot myvatn natural nature orange park red rock simmering smoke soil solfataras steam sulfur sulfurous tourist turquoise vent volcanic volcano water lakes springs vents