boiling and steaming grey mud pots and orange sulfur soil in hverir, myvatn geothermal area, iceland

active area blue boil bubble crack crater dramatic field formation fumarole gas geology geothermal grey hole hot spring hverarapara hverir iceland icelandic krafla lake land landmark landscape mineral mountain mud pot myvatn natural nature orange pond pool red rock sky smoke soil steam sulfur sulfuric tourist vent volcanic water boiling steaming pots north east