Gunsan was a small fishing village on the banks of the Geum River, near where the river spills into the Yellow Sea. It sits on the fertile western "Honam" plain where much rice is harvested. Gunsan became a port in the late 19th century largely due to pressure from the Japanese on the Koreans to ship rice to Japan. In 1899, Gunsan Port officially opened up to international trade. Gunsan City was largely settled by Japanese during the period of the Japanese occupation. The old (now demolished) City Hall and the Customs House are of Japanese construction. After liberation from the Japanese in 1945, Gunsan began to grow slowly.