Gunsan, city and port, North Jeolla do (province), western South Korea. Gunsan is situated on the province’s Yellow Sea coast 25 miles (40 km) west-northwest of the provincial capital, Jeonju, and 7.5 miles (12 km) from the mouth of the Geum River.
From the time of the Joseon (Yi) dynasty (1392–1910), it was noted as a rice-shipping port, and much of its commercial activities centered on processing, storing, and transporting rice grown on the rich Geum River plain. Gunsan’s manufactures include automobiles, electronics, metal products, and food products, and a free-trade zone was established in the early 21st century. The Saemangeum Seawall, a 21-mile- (33-km-) long dike linking Gunsan with Byeonsan Peninsula National Park to the south, was completed in 2010; the world’s longest seawall at the time of its opening, it made possible the reclamation of some 155 square miles (400 square km) of low-lying farmland and freshwater lakes.
Gunsan also hosts a significant U.S. military presence, with the Kunsan Air Base being located nearby. Established in 1938 by the Japanese during their occupation of Korea, the base was expanded and used extensively by the United States Air Force during and after the Korean War. It has since remained an important U.S. military installation in the region. It is one of two major U.S. Air Force bases in South Korea, the other being Osan Air Base. Pop. (2020) 269,023.