It’s a caldera lake formed 7000 years ago by the volcano eruption.
The depth is 211.5m , the transparency is 19m , very clear.
The surface color is deep blue because the water becomes very deep from the edge.
![Mashu lake, the blue lake](https://i0.wp.com/nobu-tokyo.com/wp-content/themes/the-thor/img/dummy.gif?w=1140&ssl=1)
It’s always covered by the’fog’ , people call it as ‘ foggy Mashu lake ‘ . There is a romantic popular song as ‘ foggy Mashu lake’ too.
![Mashu lake, foggy Mashu lake](https://i0.wp.com/nobu-tokyo.com/wp-content/themes/the-thor/img/dummy.gif?w=1140&ssl=1)
If you want to feel the mysterious atmosphere of Japan, check out here!
I’m Nobu, one heart enjoy together!!!
![Mashu lake in east Hokkaido, one of the most clear lakes in the world](https://i0.wp.com/nobu-tokyo.com/wp-content/themes/the-thor/img/dummy.gif?w=1140&ssl=1)