At around 3.3 million residents as of 2024, Busan, also known as Busan Metropolitan City, is the second most populous city in South Korea after Seoul. Previously written as Pusan, it is the economic, cultural, and educational hub of southeast Korea. Its port is the busiest in South Korea and the sixth busiest worldwide.[a] The greatest industrial area in South Korea is the “Southeastern Maritime Industrial Region” that surrounds it, which includes Ulsan, South Gyeongsang, Daegu, and a portion of North Gyeongsang and South Jeolla.