sulfur hot spring at oyunuma lake, noboribetsu onsen, hokkaido,

boiling fog fountain geography geological geology geothermal geyser heat hiyori hokkaido hot hotspring japan jigokudanai lake landmark landscape mineral mountain national natural nature noboribetsu onsen oyunuma park pond scene scenery scenic shikotsu spring steam sulfur sulfurous sulphur thermal tourism toya travel valley view water