Taking Himeji-jo Castle as an example, only two structures, the four-roof donjon and the connected four-roof watari-yagura (the roofed-passage turret), have been designated national treasures; the other turrets, gates, walls and so forth of the castle complex have been designated important cultural properties.
姫路城の場合を例にとれば、国宝指定物件は4棟の天守とそれらをつなぐ4棟の渡櫓（わたりやぐら）のみであって、これら以外の櫓、門、塀などは重要文化財となっている。