Upvote:2
You arenβt visa free to South Korea. You can only transit without a visa if you stay in the departures area. You will need to apply for a visit visa to exit the airport.
Upvote:2
Officially, having a US visa allows you to exit Incheon airport during a transit, but only when you are traveling to or from the US.
Anecdotally, I have heard that Korean immigration officials have allowed transiting passengers with a US visa to leave the airport even if they are not traveling to or from the US. I would not count on this, though, as it is very likely a mistake.