A fence or wall may be constructed on top of the earthen wall and sakamogi (fence made of thorny or steepled branches ) was placed on a slope to prevent enemies from entering and reinforced defenses . 土塁の上部に柵や塀を設けることもあり、斜面には逆茂木(さかもぎ)を置いて敵の侵入を阻むなど、防備は厳重を極めた。