Tatsumaki Jigoku has a geyser that shoots off about every 35 minutes.
The sprawling, wooded and water-crossed Usa-jingū, the original of which dates back some 1200 years, is the chief shrine among some 40,000 in Japan dedicated to the warrior-god Hachiman. It’s a 4km bus or taxi ride from Usa Station (get off at Usa-Hachiman-mae), on the JR Nippō line from Beppu. Parking costs ¥400.
In the smaller group of hells, Chi-no-ike Jigoku has photogenic red water.