Seoul Gimpo International Airport — Seoul, South Korea

Before Incheon opened in 2001, GMP served as South Korea's principal international gateway, and it still functions as Seoul's closer-in airport for domestic hops and a cluster of short-haul international routes to nearby Asian cities. Its most distinctive service is the shuttle connection to Tokyo's Haneda Airport, valued by business travelers for linking two downtown-adjacent airports rather than the more distant Narita or Incheon alternatives. Additional international flights reach destinations in China and elsewhere in Japan, though the bulk of Gimpo's traffic remains domestic, connecting the capital to Jeju Island and other regional cities. Located in western Seoul, the airport traces its origins to the Japanese colonial period, making it one of the oldest continuously operating airfields in the country. Its compact scale contrasts sharply with Incheon's sprawling international complex nearby.