-jou or shiro

castle

The castle, along with shoguns and samurai, symbolize feudal Japan. Castles were built in strategic locations, such as on the tops of hills, and near important features, such as shrines or temples, large markets or ports, or where important roads crossed. The main castle was usually surrounded by moats and massive walls and typically consisted of several compounds. Notice the shachi-hoko on the roof. The term for castle is shiro, but when attached to the name of a castle it is -jou, such as in Matsue-jou.

Secrets of the Samurai
Ratti & Westbrook