It seems Kami-Amakusa city, Kumamoto prefecture.
(I guess the map is a bit rotated clockwise.)

Kumamoto:
http://en.wikipedia.org/wiki/Kumamoto_Prefecture

Kami-Amakusa:
http://en.wikipedia.org/wiki/Kami-Amakusa%2C_Kumamoto

"266" is a route number.
The building at the center of the map is Kami-Amakusa police office. (as a landmark?)

By the way, where are you going to?

私は釣りをしに行きます。

Here?
http://www.turi-ebisumaru.com/access/index.htm

More precise maps...

http://www.mapion.co.jp/c/f?grp=a4map&uc=1&scl=250000&icon=mark_loc%2C0%2C%2C%2C%2C&coco=%2C&nl=32%2F34%2F47.742&el=130%2F24%2F21.665&pnf=1&size=640%2C740&icon=a4m01_250000%2C%2C%2C%2C%2C&coco=320%2C370&map.x=321&map.y=378

http://www.mapion.co.jp/c/f?nl=32/34/41.084&el=130/24/23.471&pnf=0&uc=1&grp=a4map&coco=32/34/47.742,130/24/21.665&icon=mark_loc,,,,,&coco=,&icon=a4m01_70000,,,,,&scl=70000

The block number of the address written on the website is 7625. So I guess it's somewhere around this but not sure.
http://www.mapion.co.jp/c/f?grp=a4map&uc=1&scl=25000&icon=mark_loc%2C0%2C%2C%2C%2C&coco=32%2F34%2F47.742%2C130%2F24%2F21.665&nl=32%2F34%2F47.221&el=130%2F24%2F15.244&pnf=1&size=640%2C740&icon=a4m01_25000%2C%2C%2C%2C%2C&coco=320%2C370&map.x=327&map.y=366

Maybe it's a very small port.