Jeju, city and provincial capital, Jeju do (province), on the northern coast of Jeju Island, off the southern coast of South Korea. Jeju is the island’s largest city and has its only airport, which handles both domestic and international flights. The political, commercial, and cultural center of the island since it was an independent kingdom in ancient times, Jeju developed as a seaport after 1913. Port facilities were rapidly constructed after 1946. Industries include canning and the manufacture of marine products, spirits, and starch (from sweet potatoes). Jeju National University (1955) is located there. Among the city’s historical sites is Samseong-hyeol (“Caves of the Three Clans”), the legendary cradle of three old families (Go, Yang, and Bu) whose progenitors were said to have emerged from the ground to found the ancient kingdom of Tamna, which existed independently until its absorption by the Goryeo dynasty in 938 ce. Pop. (2020) 492,306.