Shuri-jo, or 首里城, is a castle located in southern Okinawa which I visited last week while on a trip to the Japanese island. The structure itself is rebuilt, having been used as a Japanese military headquarters during the 1945 battle and subsequently destroyed during the fighting. It dates back to the 14th century, during which it was part of not Japan, but the Ryukyu Kingdom. The Ryukyu culture, which is similar in many ways to Japan through language and culture, played a central role in trade in the region. It was, however, taken over and annexed by the 19th century as Okinawa became Okinawa Prefecture.