"Azumino"in Nagano Prefecture

I've stayed in Nagano prefecture about two weeks for sketch.
This area is called "Azumino".
"Azumi" means the sea,in an ancient Japanese language.
In this area as known as high mountains area in Japan.
You can see northern Japanese alps"kita-alps mountains".
It is wondering why named "Azumino" means field of sea.
Because, in Nara period,
A family called "Azumi-zoku"lived in the Inland Sea of Japan "Setonaikai".
They emigrated to Azumino by orders of an emperor of Yamato dynasty.
Now, Azumino famous area as beautiful landscape and the riches of nature.