Hishi Yagura, or Diamond Turret, is a three-story building, the sides of which are in a ”hishi”, or diamond shape, with angles of 80 and 100 degrees. It was the tallest building in Ni-no-maru, the second enclosure, and was the symbolic building in Kanazawa Castle, distinguished by its smart defense system called ”ishi-otoshi”, or stone-dropping, and its gorgeous appearance.
Another feature of this building is its lead roof tiles. These tiles are 1.8 millimeters thick, and made of lead mixed with a little copper. Finally, the outside of this wall is called ”Namako Kabe,” or the Sea Cucumber wall. It is made by attaching flat tiles to the earthen wall with plaster.