Usually, a Japanese castle has a main keep (tenshukaku) and one or more smaller towers (yagura). Depending on how these two structures are connected, several types of castle architecture are defined and I already presented the Fukugoshiki style, where the main keep is connected directly to a smaller donjon.
Today, I would like to show you the Renketsushiki style, with the main keep connected to the tower through a roofed passage, called in Japanese watari yagura. In this photo, taken at the Matsumoto castle, you can see that the tower from the the right side (Inui Kotenshu) is connected with the main keep by the watari yagura.
Yesterday’s Japan Photo: