Matsushiro Castle Ruins, Nagano.

“Matsushiro Castle (Matsushiro-jō), formerly known as Kaizu Castle (Kaizu-jō), is a Japanese castle [and] a registered National Historic Site of Japan. The first castle on this site was built in 1560 by Yamamoto Kansuke, under the direction of Takeda Shingen and was called Kaizu Castle. Kōsaka Danjō (Kōsaka Masanobu) a Takeda clan retainer, was its first commander.”