Hot Springs of Beppu
Beppu (Oita Prefecture) is a town famed for its abundance of natural hot springs (onsen). Scores of bathhouses pepper the town, most charging only 100 yen (~1USD) for entry.
There are also areas of natural springs that are unsafe for humans to enter. These tears in the earth emitting thick primordial steam into our modern world are referred to by the Japanese as jigoku (地獄), hells. Pictured above is the Chinoike-jigoku, the hell of blood.