Site of the Masugata
Slowing Down the Enemy
The road at this point makes a 90-degree turn. Originally designed for the defense of Japanese castles, this sort of sharp turn was a deliberate device meant to deprive an enemy of forward momentum and give defenders an opportunity to fire down at them from the upper stories of nearby buildings. This feature was known as a masugata (literally “box shape”), after masu, a square wooden box used to measure rice.
All the post towns on the Nakasendo had masugata. Even after gaining control over all of Japan in 1600, the shogun Tokugawa Ieyasu remained suspicious of the feudal lords of western Japan whom he had defeated, and saw the post towns as defensive locations where his forces could fight off enemies. At the same time, the masugata could also help defend the post towns against incursions by lawless elements.