Tottori Castle

Tottori Castle (鳥取城, Tottori-jō) was the central castle of the Tottori han (fief) in feudal Japan. It was a yamashiro, or "mountain-castle", built into the mountain itself, using natural obstacles and defenses to a greater extent than man-made walls. Little remains of the castle aside from parts of the stone wall, and one gate, reinforced with iron and featuring spikes on the outside of the doors to help protect against attackers.

• http://en.wikipedia.org/wiki/Tottori Castle