Taikaku layout was considered ideal for defending against outside attack. It consisted to build a castle in three tiers. The bottommost and largest tier, known as the sannomaru, was built directly upon the ground. The second tier, the ninomaru, was built up on top of the first and was surrounded by an inner moat. The third tier, the honmaru, was elevated above the second tier and placed adjacent to the primary walls, and was separated from the other tiers by another gate and inner wall.