Busan, officially Busan Metropolitan City, is the second most populous city in South Korea, after Seoul; it has a population of over 3.3 million as of 2024. It is the economic, cultural and educational center of southeastern South Korea, with its port being South Korea's busiest and the sixth-busiest in the world. The surrounding "Southeastern Maritime Industrial Region" is South Korea's largest industrial area. The large volumes of port traffic and urban population in excess of 1 million makes Busan a Large-Port metropolis using the Southampton System of Port-City classification. As of 2025, Busan Port is the primary port in Korea and the world's sixth-largest container port.