One of Beppu’s “7 Hells”, Umi Jigoku is a geothermal pool of water in a shade of cobalt blue.
Entry to the park containing the hot pool is 400, although a “7 hell” concession ticket for 2,000yen is also available.
Also within the park is a shrine, a tropical greenhouse heated with “gases from hell”, a smaller red colored pool and an ashi mizu bath which you can dip your feet in. Bring a small towel with you so you don’t end up with wet shoes for the rest of the day.
Parking is free.