Usan-do (, ) is a historical name for an island in the

Sea of Japan The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it ...

described in Korean records. It was part of the ancient state of

Usan-guk 280px, "Samguk Sagi" Book 04. Silla's Records. In 512, Usan-guk（于山國）was Ulleungdo（鬱陵島） Usan-guk, or the State of Usan, occupied Ulleung-do and the adjacent islands during the Korean Three Kingdoms period. According to t ...

, but its exact identity is disputed. It may refer to: * Jukdo, a Korean island 4 km east of Ulleungdo. * The

Liancourt Rocks The Liancourt Rocks, known in Korea as Dokdo () and in Japan as Takeshima (), are a group of islets in the Sea of Japan between the Korean Peninsula and the Japanese archipelago administered by South Korea. The Liancourt Rocks comprise two ...

, a disputed group of islets now known as ''Dokdo'' in Korea and ''Takeshima'' in Japan.

Old Korean maps of Usan-do

file:八道総図.jpg, Joseon map (1530) file:Ulleungdo and Usando.jpg, Joseon map (1530): Ulleungdo () and Usando () file:DaedongyeojidoUlleungdo.png,

Kim Jeong-ho Kim Jeong-ho (; 1804–1866?) was a Korean geographer and cartographer. His art name was Gosanja (). He was born in Hwanghaedo. It is believed that he walked the entire length and breadth of the Korean peninsula, through mountain and valley ...

" Daedongyeojido" (1861): Ulleungdo () and Usando () file:East of Ulleungdo and Usando.jpg, Kim Jeong-ho "Daedongyeojido" (1861): East of Ulleungdo () and Usando () file:DaehanJeondo.jpg, A map by the

Korean Empire The Korean Empire, officially the Empire of Korea or Imperial Korea, was a Korean monarchical state proclaimed in October 1897 by King Gojong of the Joseon dynasty. The empire lasted until the Japanese annexation of Korea in August 1910. Dur ...

(1899): Ulleungdo () and Usan () as Jukdo file:Jukdo Island.png, Aerial photograph of Jukdo Island (for reference)

Old Korean maps of Usan-do

See also