The Aoi-ike is a really blue pond.
The “Aoi-ike” which means “A blue pond” in Japanese (Aoi -> blue, ike -> pond).
It is located in the Biei and it takes about 30 min by car to get there from Asahikawa.
The Aoi-ike has been popular in the past few years in japan,
because of the beauty of the pond with blue water.
(But I was wondering the Aoi-ike is really blue pond.)
My parents happened to visit us last week,
so I took them to the Aoi-ike.
For us, it was the first time to see the Aoi-ike.
When I saw it, I was impressed the beauty of the blue pond.
It was really blue and amazingly beautiful.
From the explanation of the guide plate,
the Aoi-ike is not the pond that has been naturally made.
In 1988, a dam was made around there to prevent the Biei people from the volcanic hazard.
After the construction of the dam, the water was gradually gathering at the outside of the dam, making a pond with blue water.
There are some opinions explaining why the water is blue,
however, the exact mechanism is not fully understood.