Nanao Castle - Credit: Wikimedia Commons
was a Muromachi period yamajiro-stype Japanese castle located in what is now the city of Masuda, Shimane Prefecture, in the San'in region of western Japan. Its ruins been protected by the central government as a National Historic Site since 2004 together with the Miyake Odoi fortified residence as the "Masuda clan fortification ruins". Read more on Wikipedia
Source: en.wikipedia.org