Busan (Korean pronunciation: [pusan]), formerly romanized as Pusan and now officially known as Busan Metropolitan City, is South Korea's second-most populous city after Seoul, with a population of over approximately 3.4 million inhabitants.[3] It is the economic, cultural and educational center of southeastern South Korea, with its port—Korea's busiest and the fifth-busiest in the world[a]—only about 193 kilometers (120 mi) from Japanese islands of Kyushu and Honshu. The surrounding "Southeast Economic Zone" (including Ulsan and South Gyeongsang) is South Korea's largest industrial area.