As I wrote in the article on Beppu, one of the main attractions of this city of Kyushu is the Jigoku Meguri tour. These are scattered around the city: six of them up north, in the District of Kannawa, and two more near the coast to Shibaseki.
These very special onsen each have specific benefits, but you can not swim in them. Their temperatures frequently exceed 100°C. However everyone can admire them, or buy salt or soap created on their basis, which are exported worldwide, mainly in organic products shops.
The tour can be done through the day (they close at 5PM) for 2000 yen. The 8 Hells are named: Umi Jigoku, Shiraike, Chinoike, Oniishibozu, Yama, Oniyama, Kamado and Tatsumaki. Here are some pictures (and a video at the end of this post):
Here is a video footage of Beppu Jigoku Meguri – onsen hells :