An aerial view of Shuri-jo Castle Park in Naha, Okinawa Prefecture, on Oct. 20. A makeshift structure stands on the site of the castle’s ruined Seiden main hall.

The Seiden hall and other facilities were only rebuilt in 1992 as part of a national park. Shuri-jo Castle, along with other castle ruins in Okinawa, were inscribed on the UNESCO World Cultural ...