At a tad under 14 meters from the ground to the tip of the flames, its not the tallest Fudo Myoo statue by any means but it is still quite impressive.
It's located in front of Ryusho-ji, a Shingon temple, number 64 on the pilgrimage I walked around Kyushu. Its on the lower east slope of Mount Unzen, the active volcano in the center of the Shimabara Peninsula in southern Nagasaki.
Two smaller Fudo statues, with quite distinctive faces, flank the main statue.
Miniature Fudo's left by worshippers are lined up at the base.