Stone walls are an impressive, familiar and iconic sight surrounding samurai castles. Although often taken for granted and overlooked by the casual visitor, they played an integral part in improving the castle’s strength and providing a visual display of power, but their history is relatively modern, dating back to around 1563.
Before stone walls were incorporated into castle design, early castles consisted of piled earthen mounds, most of which was dug when forming the moats and trenches around them to form protective barricades. Indeed, this can be seen in the kanji for castle 城 which consists of the compounds for earth, tsuchi 土 and nari, 成 or, “to become”. 土+成=城