Ro-no-Mon is a koraimon (gate) located on the north side of Mikuni-bori, beyond ‘Ino-no-Mon’, and is characterized by its massive structure with side doors. It was built in the old style of the Keicho period and is decorated with “suji-tetsu manju-kinmono” and “hachi-soukinmono”. On the east side of the gate, there is a stone wall and an earthen wall, with a narrow space in the earthen wall to allow defense from the inside. In addition, diversion stones and engravings can be seen inside the gate, giving it a historical flavor. On the other hand, the stone wall and earthen wall on the west side are built very high, reinforcing the defense against enemy intrusion. Interestingly, the “Ro-no-mon” also has a tragic history of being accidentally blown up. Thus, the “Ro-no-Mon” is one of the most important remains that tell the story of the defensive structure and history of Himeji Castle.