Naha's top attraction was first constructed between the 13th and 14th centuries and served as the epicenter of the Ryukyu Kingdom for about 500 years, until the establishment of Okinawa Prefecture in 1897. Serving as both a residence for the king and an administrative and religious center, it shows architectural influences from both China and Japan but is uniquely Ryukyuan in style. Unfortunately, the original structures were destroyed in the Battle of Okinawa, but as a reflection of the site's importance, this partial re-creation, along with eight other historic properties in Okinawa Prefecture, has been designated as a World Heritage "Gusuku Sites and Related Properties of the Ryukyu Kingdom." Lots of information and pamphlets in English explain the significance of what you're seeing; you'll probably spend about an hour here, longer if you catch one of the 40-minute traditional court dances (performed, at last check, on Wed, Fri-Sun, and holidays at 11am, 2pm, and 4pm).