To use public transportation in Seoul, Incheon, and Gyeonggi, you need a transportation card. You can purchase it at the airport.
From Incheon International Airport,
- By bus, take Airport Bus 6020, or 6020-1 at GATE4. (It takes 1 hour 10 minutes. It costs KRW 13,000.)
- By subway, after taking the Airport Railroad, transfer to Line 9 at Gimpo Airport Station, transfer to Line 3 at Express Bus Terminal Station and get off at Seoul National University of Education Station. (It takes 1 hour 40 minutes. It costs KRW 4,150.)
From Gimpo International Airport,
- By subway, after taking Line 9 at Gimpo Airport Station, transfer to Line 3 at Express Bus Terminal Station and get off at Seoul National University of Educaiton Station. (It takes 1 hour 10 minutes. It costs KRW 1,550.)