Your usual maps app may not help you here
South Korea restricts the export of detailed mapping data, and the practical result is that Google Maps does not give you the full turn by turn navigation you are used to. Visitors end up on Naver Map or KakaoMap instead, which are excellent but which you will be downloading, setting up and learning on arrival. Doing that in the airport on a connection that already works is a great deal easier than doing it on hotel Wi-Fi after a long flight.

