The Blood Pond Hell (血の池地獄) is one of Hell Tour of Beppu Onsen, Oita Prefecture. This blood color is caused by Iron oxide. The temperature of the Onsen water is 78 celcius and contains a lot of iron. It is a very large pond; 1300 square meters wide and 30m deep. The spring produces one million 800 thousand litres of water every day. It Is desiginated as the national scenic beauty.
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
1. at Beppu Station.
2. Use local bus 2,5,24 to Kannawa Onsen.
3. Change Bus to Chinoike Jigoku.
400 JPY
30 min
New Wave Samurai Movie. 
映画好き集まれ！ 
Blood Pond Hell is the oldest Onsen Hell in Japan. Iron Oxide and Magnasium oxide are created underground of this pond with high temperature and pressure that couse the red color.
There is foot Onsen in this pond.
Official web site:http://www.beppu-jigoku.com/images/English0.pdf