pine near hot spring jigoku, multi-colored volcanic pool of boiling water in kannawa district in beppu, japan

acid asia beppu boiling danger destination environment famous fog fumarole gas geological geothermal heat hell hot japan japanese jigoku kyushu landscape mineral mist mud nature oita onsen outdoor pine place pond pool prefecture sea smell smoke spa spring steam stone sulfuric sulphur temperature thermal tourism travel umi unpleasant volcanic water