Yes, they share the same airport.
Incheon and Seoul are in the same metropolitan area. It takes about an hour to get from downtown Seoul to Incheon airport though.
The Incheon Airport, which serves the Seoul-Incheon Metropolitan area, is an island airport.
The capital of South Korea is Seoul. However, Seoul is not a coastal city, so MacArthur made his landing in the city of Incheon. Incheon has since become part of the Seoul metropolitan area, but remains a distinct city.
Most South Koreans live in urban metropolitan areas. The Seoul-Incheon metropolitan area alone is responsible for about half of South Korea's population.
The floor area of Incheon International Airport in Seoul is 496,000 m2 (5,340,000 sq ft).
80% live in urban areas, cities, basically.
Seoul is South Korea's largest city. The Seoul metropolitan area is half of South Korea's population.
The flight distance from Seoul Metropolitan Area to Taipei Songshan Airport is about 919 miles / 1,479 km
The area of Incheon is 1,029.43 square kilometers.
The largest metropolitan area in the world in terms of population is the Kanto Major Metropolitan Area in Japan, including a.o. Tokyo, Yokohama, Kawasaki, Saitama and Chiba, and with over 35 million inhabitants.
Seoul is the capital of South Korea and the second largest metropolitan area in the world. Pusan is the second largest city in South Korea.
In both square mileage and population, Sydney, Australia, is bigger than Seoul, South Korea. Square miles: Sydney, Australia: 4,689 sq miles Seoul, South Korea: 233.7 sq miles Population: Sydney, Australia: 4.579 million Seoul, South Korea: 9.82 million