Is it necessary to open a data package to go to Jeju Island?

Whether it is necessary to activate a data package when going to Jeju Island depends on your specific needs.

If you need to access the Internet during your trip, such as looking for maps, sending emails, etc., then it is necessary to activate a data package. In addition, if you need to use some APPs that require Internet access, such as translation APPs, navigation APPs, etc., you also need to activate a data package. However, if you are simply sightseeing and do not need to use the Internet, or you are only using Wi-Fi in the hotel, then there is no need to activate a data package.