Okinawa has several castle ruins, which are united as one UNESCO World Heritage Site. They date back to the Gusuku period (12th-15th century), when Okinawa was ruled by three kingdoms. Nakijin Castle was built in the late 1200s and were the castle for the northern kingdom, Hokuzan. In 1416 the Hokuzan Kingdom was invaded by the middle kingdom, Chuzan, which then went on to unify Okinawa in 1429, as part of the newly established Ryukyu Kingdom.
Today the castle ruin is known for its rebuilt outer stonewalls, which gives a good picture of how big the castle actually has been, but the rest is left to the imagination. It's surrounded by lush forest and with splendid views the northern part of Okinawa and the East China Sea.