Tamagawa Onsen/Tamagawa hot spring (¥500 per person)
We visited Tamagawa Onsen, which is always featured on Japanese TV programs as one of the famous Japanese hot springs. There were three hot spring hotels in Tamagawa Onsen, Tamagawa Onsen hotel, New Tamagawa Onsen hotel(only a short drive away from Tamagawa Onsen, about 10 minutes drive) and Bunanomori Tamagawa Onsen hotel (near New Tamagawa Onsen). Tamagawa Onsen hotel is always crowded with hotel guests so I recommend the other two hotels.
The hot spring water is extremely acidic, about ph1.2, and it is the highest acid levels among all Japanese hot springs. So if you have any kinds of cuts and scratches, you would feel a lot of pain! However, each hotel has 3 kinds of bathtubs with different concentration levels, 0%, 50% and 100% of the natural source. If your skin is sensitive, you might have a skin irritation so I really recommend the 50% concentration level otherwise you will wash away the components of the hot spring.

Hachimantai
After taking a hot spring, we headed for Iwate prefecture by crossing over Hachimantai. Hachimantai is a volcanic mountain between Akita and Iwate prefecture. It is one of the most famous thermal regions in Tohoku destrict and it is well-known for its geothermal activity and characteristic hot springs. We saw plenty of dense steam coming from the ground everywhere. And I felt that the air was filled with the smell of sulfur.

View on the way back to Iwate
We were supposed to be able to see Mt.Iwate, which was the highest volcanic mountain in Iwate, on the left side. But there was a lot of cloud cover over the mountain.

center,right: There was a dark green extensive forest on the other side.