archipelago, Shimane ken (prefecture), Japan, lying in the Sea of Japan off the coast of Honshu. The largest island is Dōgo; the three smaller isles (Chiburi, Nishino, Nakano) are collectively known as Dōzen. The four islands have a combined coastline of 223 miles (359 km) and an area of 134 square miles (348 square km). The chief town is Saigō, on the island of Dōgo, about 50 miles (80 km) from the Honshu port of Sakaiminato. Fishing is the main economic activity.

The archipelago is celebrated in Japanese history because its possession was much disputed during the feudal period and because two emperors were banished there by the Hōjō regents in the 13th and 14th centuries. The islands now form part of Daisen-Oki National Park. Pop. (1980) 29,478; (1990) 27,493.