Zao Onsen is located on the Zao mountains. It is located 880m high from the sea level. Therefore, it was called Takayu, highland Onsen.
There are many hotels in Zao. Some of them don't have Onsen, but during the ski season, many people visit Zao to enjoy ski and Onsen at the same time. There are also 7 public Onsen.
Zao is one of the biggest Ski resort in Japan. There are 14 slopes and 12 courses in Zao, and snow stays middle of April.
In summer, it becomes the popular hiking spots and many people visit Zao. At the top of Mt. Jizo, you can see great view of Yamagata and Miyagi. You can see a beautiful lake, called Okama from there as well.