Traffic in South Korea is heavily concentrated: Incheon International Airport (ICN) alone handles about 71.2 million passengers a year, roughly 57% of the 125 million across the 3 airports listed here. That pattern is typical of a country with one dominant hub carrier feeding a single gateway.
Between them these airports operate 8 runways serving 2 cities, all on a single national clock. Every airport below links to a live map of aircraft observed within available ADS-B coverage around the field.
The next airport in the ranking is Jeju International Airport (CJU) at about 29.7 million passengers. The gap to ICN is 41.5 million, while the three busiest airports account for roughly 100% of traffic represented by this list. Most listed traffic is therefore concentrated at the top of the network.
The airports are spread across roughly 4 degrees of latitude and 0 degrees of longitude. The network is geographically compact enough that most domestic sectors remain comparatively short. Field elevations vary less dramatically than they do in the world's mountain-airport networks. The average across this selected set is 2.7 runways per airport.
Read airport by airport, the selected South Korea network is not interchangeable: Incheon International Airport (ICN) has 4 runways and about 71.2 million annual passengers, Jeju International Airport (CJU) has 2 runways and about 29.7 million annual passengers and Gimpo International Airport (GMP) has 2 runways and about 24.0 million annual passengers. Those differences matter when comparing a live map. A larger passenger total indicates schedule scale, while runway count describes physical layout; neither number by itself proves how delayed, connected or operationally efficient an airport will be on a particular day.