Although steep mountains are desirable to construct fortifications that are expected to be built on places effective for defence, they are difficult to live; thus, fortifications were established distant from the settlements that they served to defend.
要塞は、防御に有利な地形に築くことが望ましく、険しい山はその条件を満たすが、反面住むには不便で、守るべき対象である人の居住地から離れている。