ICAO airport code

Map of the world's ICAO classifications according to the first letter of its ICAO airport code
Map of countries classified with ICAO airport code prefixes and subnational regions with their respective second ICAO letter
Flag of the ICAO

The ICAO airport code or location indicator is a four-letter code designating aerodromes around the world. These codes, as defined by the International Civil Aviation Organization and published quarterly in ICAO Document 7910: Location Indicators, are used by air traffic control and airline operations such as flight planning. ICAO codes are also used to identify other aviation facilities such as weather stations, international flight service stations or area control centers, whether or not they are located at airports. Flight information regions are also identified by a unique ICAO-code.