In December 2000, nine Okinawan sites were inscribed as "Gusuku Sites and Related Properties of the Kingdom of Ryukyu" as a UNESCO World Cultural Heritage Site.
The 9 inscribed sites: 1. Shuri Castle Ruins — Political and cultural center of the Ryukyu Kingdom 2. Nakagusuku Castle Ruins — Battleground of the Three Kingdoms rivalry 3. Katsuren Castle Ruins — Hilltop castle overlooking the sea 4. Zakimi Castle Ruins — Beautiful refined arch gates 5. Nakijin Castle Ruins — Residence of the Northern King, famous for cherry blossoms 6. Sefa-utaki — Ryukyu's holiest sacred site 7. Shikinaen — Villa garden of the Ryukyuan royal family 8. Sonohyan Utaki Stone Gate — Entrance to the utaki near Shuri Castle 9. Tamaudun — Mausoleum of the Second Sho Dynasty
"Gusuku" refers to castles in Okinawa and Amami, characterized by stone-piled fortifications built in the 14th to 16th centuries. Unlike mainland Japanese castles, they typically have no donjon — only stone walls remain.
