You know that Korea has one of the fastest internet speed in the world. And you can live with plastic money instead of real money.
Korea Pass is easy and convenient card for foreigners who will travel Seoul more than one week to shop and ride public transportation and taxi.
Korea Pass is a prepaid tourism card designed by Korea’s Ministry of Culture, Sports and Tourism(MCST) and the Korean Tourism Organization(KTO). So it is trustworthy and also convenient to hold during your travel.
You can buy it at Immigration in Incheon Int’l Airport or some other place.
Please find more information about Korea Pass from below site.