That's a tiny bit late while in the day in order to do A lot culturally, but you could potentially go into the town (I might advocate Hongdae, as it's closest sort the airport) and enjoy a pleasant dinner and afterwards a walk within the a lot more energetic region of town just before intending to bed very early (you'll want to get 분양 up around five:30am to have the ability to get within the coach by 6am).
I'm US citizen and can fly air copyright to ICN, I will have 22 hrs layover and alter to Asiana airline to China.
Indeed, the Terminal 2 Resort operated by Walker Hill would be the one particular located in the terminals inside the airport, so you won't have to have a Q-Code to remain there.