The word "castle"usually means the inner castle, while the precise boundaries of the sogamae, the outer castle, were unclear since they included natural geographical features (mountains and rivers).
普通、「城」という場合は、内郭のみを指し、外郭である総構えは天然の地勢（山・河川）をも含むため、どこまでをいうのか不明瞭なものもあった。