Japanese religious pond

hello
I went to Maruike-sama in Yamagata Prefecture, Japan

There is an anecdote that the fish that live in this pond have one eye.

An old samurai washed his arrow-shot left eye in this pond
The pond turned bright red, and since then all the fish in the pond have had one eye.

Fallen trees in water are not rotting
looks like a giant snake or dragon

The water in the pond looks very beautiful emerald green