Gunsan, also romanized as Kunsan, is a city in Jeonbuk State, South Korea. It is on the south bank of the Geum River just upstream from i…Gunsan, also romanized as Kunsan, is a city in Jeonbuk State, South Korea. It is on the south bank of the Geum River just upstream from its exit into the Yellow Sea. It has emerged as a high-tech manufacturing industrial city and an international trade seaport that is approximately 200 km southwest of Seoul on the midwest coast of the Korean Peninsula.