Ninomon Gate was located on the pathway between the front stone foundation and stone foundation to the left. The structure of this gate included a gate on the bottom, and a guardhouse that sat on top. Adjacent walls were built on the stone foundations found on either side of the building. When going under the gate, the tall stone foundations formed a square-shaped space that made it a very difficult structure to move through. The strong structure not only defends against potentially invading enemies, but also provides a safe and protected place for troops to stay when on the attack.
This type of entrance was found to be constructed within many castles from the early modern period. Ninomon Gate was the only gate built utilizing this particular structure at Hamada Castle, and made it a very important gate in front of the "Honmaru."