Cheju (jā`jo͞o), Jap. Saishu, island and province of South Korea (1995 pop. 505,442), c.700 sq mi (1,810 sq km), c.60 mi (100 km) SW of the Korean peninsula. Korea's largest island, Jeju is of volcanic origin and rises to c.6,400 ft (1,950 m) in Hallasan, an extinct volcano. The production of marine products, spirits, and starch are the main industries; tourism became important beginning in the late 20th cent. Dairy farming, livestock breeding, and citrus growing are also important occupations on the mountainous, heavily wooded island; agriculture is practiced on the slopes and in the valleys. The island was often used as a place of exile. In 1948–49 some 30,000 islanders were killed by the South Korean army in a campaign against supposed Communists; the truth about the massacres were denied until the 1990s. After the Korean War Jeju became a haven for refugees. There are air connections and ferry links with mainland Korea and Japan. Jeju (1995 pop. 258,509), on the north coast, is the capital and chief city.