Chinoike Jigoku, Beppu Overview
A pond of red clay-laden water, the oldest natural hot spring recorded anywhere in Japan, appearing in documents more than 1,300 years old. It is the only one of the seven that is red, which is reason enough to make the trip. Note that it sits in the Shibaseki cluster about 3 km from the five hells in Kannawa, so you need a bus between them rather than a walk.
