Kon-ya Jigoku - “Dyer’s Vat Hell”
Japan is full of steaming volcanic valleys and marshlands called jigoku, or “hells.” The Kon-ya Jigoku, a steaming pond of mud that is shaped like a kon-ya, or dyer’s, vat, is a blistering 94°C.
The mud in the pond is formed when sulfur in the steam escaping from vents in the ground travels to the earth’s surface, forming iron sulfide sediment. The sediment then combines with deteriorated rock to form mud. Careful observation of the surface may reveal the mud bubbling from the force of the steam.