More than 100 unejo tatebori (a series of parallel trenches running up the sides of the mountain) were constructed over approximately 2 kilometers from the "Nishinomaru" to the "Demaru" (a fortress tower built far from the main castle) at Teragahana, the tip of the ridge.
「西の丸」から尾根先端、寺ヶ鼻の「出丸」跡までの約2キロメートルの間に100基以上の畝状竪堀が築かれている。