Noboribetsu Okunoyu

Noboribetsu Onsen is famous for its hot springs and Jigokudani, but this island is still a volcanic area that continues to be active.

Sulfur spring is spurting violently from the conical swamp bottom.

The surface of the swamp is as high as 75 - 85 degrees depending on the season, it looks like a yukame.

Grayish black sulfurous hot spring water violently bubbles out of the vent formed by the conical base of this pond, an explosion crater of Mt.Hiyori.

The surface temperature of it varies from 75°c to over 85°c. Hot spring activity is especially dramatic in the area in front of the pond and around its center, giving the place the appearance of a kettle on the boil.