Gimpo International Airport (RKSS/GMP), Seoul, South Korea has 2 private jet terminals serving business and general aviation. Its 3,600 m runway takes aircraft up to ultra-long-range business jets (Gulfstream G650, Bombardier Global 7500). Customs and immigration are cleared on the field. 2 of them stay open around the clock. In-flight catering can be arranged on site. With 2 operators on the field you can compare handling quotes before committing to a turn.
Geographic coordinates: 37.55860, 126.79060. Use the FBO Finder map to plan a route and compare nearby airports.