Even though Himeji Castle was used as an administrative center, along with many other purposes, its true and intended function was as defense for the lord of the castle. This was especially the case in medieval times, and, “from its initial construction by Akamatsu Sadanori in 1346 to Ikeda Terumasa's additional building in 1613, military function dictated the design of the castle” (“HISTORY.” Colombia.edu). An example of this intended idea of defense is how the structure was tactically located atop a hill so enemies had a tough time if they were to attack. Overall, the many aspects of defense used here created large physical and psychological barriers for enemies.
To prevent enemies from advancing quickly to the castle, it had 3 lines of moats to defend against attackers, which were always filled with water. At the very least, the moats slowed attackers down, depleting enemy resources and strength over time, and gave the defenders more reaction and preparation time. Moreover, Himeji Castle’s, “fifteen-meter sloping stone walls ma[d]e it impossible for the approaching enemy to view the castle directly from the base of the walls” (“HISTORY.” Colombia.edu), and gave enemies a harder time seeing the people defending, putting them at a disadvantage. In these (and those of the castle itself) walls, two types of holes were carved out; being ishiotoshi and sama. Ishiotoshi are openings in the fortifications from which boiling water would be poured from or stones would be thrown. Much like these, the sama were also gaps in the barricades that were used as cover for riflemen or archers and could be shot through. The complex also had a sort of labyrinth of passageways built into it which would get an enemy lost or slow them down if they were unfamiliar with the layout of the castle. Lastly, the castle had a total of 84 gates fortified with wood and stone, which were very small, and only allowed a few people to move through at once. This, much like the other types of defense, slowed enemies down and made it more difficult to be attacked in large groups.