Many of Tohoku Onsen spots are related with Onsen, such as Zao Onsen is very popular ski spots as well. Also, because there are many beautiful natures in Tohoku Region, all of those spots have great nature to enjoy. Some of them are located in the deep side of mountain and called "Secret Onsen" because it so hard to visited. It is one of the best way to enjoy beautiful nature by visiting those Secret Onsen.
Zao Onsen (蔵王温泉) is the oldest Onsen exist in Japan. It has over 1900 years of history. Zao Onsen is located in Yamagata Prefecture, and it is also one of the major biggest Ski spots in Japan. There are many Onsen Hotels, public Onsen and free foot Onsen. The Onsen water of Zao has strong acidity, good for making beautiful skin. Therefore, Onsen water of Zao was called Princess Onsen. In summer, Zao is also popular hiking spots.
Tourist Info.
Water has strong acidity. be careful if you have injury.
Access
0. at Yamagata Station
1. use local bus to Zao Onsen
200 JPY
1 hr. 30 min
New Wave Samurai Movie. 
映画好き集まれ！ 
