During Nikko's winter, you can enjoy mysterious views at "Nikko Unryu Valley", as the waterfalls becomes icefalls.
The icefalls can only be seen in the coldest season, around January and February.
Please check the following URL to read notes about experiences;

• https://www.tobujapantrip.com/en/articles/18.html#utm_source=tobu_fb&utm_medium=1125&utm_campaign=unryuvalley