Jeju is the capital of Jeju Province in South Korea and the largest city on Jeju Island (population 621,550), which is the largest island off the coast of the Korean Peninsula, and the main island of Jeju Province of South Korea. Jeju city had a population of 435,413 in 2012.
Jejudo is a volcanic island, dominated by Hallasan: a volcano 1,950 metres (6,400 ft) high and the highest mountain in South Korea.