Sea Hell (海地獄) is one of Hell Tour of Beppu Onsen, Oita Prefecture. It is a Onsen spring pond with beautiful cobalt blue color. This is designated as the national scenery. The temperature of the onsen water is 98 degree celcius, The water contains iron sulfate which causes the blue color. The park of the Sea Hell uses the heat of the onsen water to grow tropical trees. Lotus and lily flowers are especially popular here.
Tourist Info.
Admission: 400 Yen for adult, 300 Yen for High school, 250 Yen Junior High, 200 Yen for kids.
Time: 8:00 to 17:00
There is parking and restroom.
8 Hell pass: 2,100 Yen for adult.
There is group discount.
Access
2. at Beppu Station.
3. Use local bus 2,5,24 to Umijigoku.
400 JPY
30 min
Let's learn MJER Iaijutsu. 
映画好き集まれ！ 
Sea Hell or Umijigoku in Japanese is one of Onsen Hells in Beppu. It has a beautiful blue color water. This Onsen spring was made about 1,200 years ago. The large pond with blue color was just like Ocean. There is a large pond that has a beautiful water lilly that bloom from May to November.
There is also foot Onsen to enjoy.
Official web site:http://www.beppu-jigoku.com/images/English0.pdf