Gimpo International Airport (IATA: GMP), the second airport serving Seoul, South Korea.
Gimpo International Airport, commonly known as Gimpo Airport (IATA: GMP, ICAO: RKSS) (formerly Kimpo International Airport), is located in the far western end of Seoul, some 15 km (9 mi) west of the Central District of Seoul. It was the main international airport for Seoul and South Korea before being replaced by icn in 2001. In 2013, 19,904,327 passengers used the airport, making it the third largest airport in Korea, as it has been surpassed by Jeju International Airport.
See here for the airport homepage.