A Castle of War and Peace
One notable aspect of Matsumoto Castle is its contrasting combination of wartime and peacetime structures.
The castle was built with the expectation that it would someday come under attack, and it has many defensive features: the rectangular loopholes in the walls would have been used to shoot bows and muskets at enemy forces. If attackers managed to cross the moat and attempted to climb the stone foundation, defenders could repel them by attacking through the ishi otoshi openings that project from the castle walls.
Later additions to the castle were added with socialization in mind. For example, the elegant vaulted ceiling and vermillion-lacquered veranda of the Moon-Viewing Tower would have been a liability during a siege. This contrast can easily be seen in the overhang that projects from the Southeast Wing. Although it resembles an ishi otoshi from the outside, the opening is completely covered by the floorboards and would have been useless during an attack.