Nijō Castle is located in Kyōto, Japan was built for Tokugawa Ieyasu, the first shōgun, but the structure wasn’t completed until 1621, ten years after Tokugawa Ieyasu’s death. Nijō Castle did serve as the Kyōto residence for the third shōgun and the shōguns who followed.
The Ninomaru Palace is divided into several rooms for guests, for audiences with the shogun, and for the shogun‘s residence. The floors connecting the rooms where guests were allowed to linger make chirping noises when walked upon when the flooring nails scrape against the wood. Legend says that these “nightingale floors” serve to provide warning that someone is moving about the palace.