I've been to Korea twice recently, really liked this place, which is not so popular and not so many information you can find about it - so I am happy to share as always in case if you will be going there.
So many cool things too see and to do, good shopping and different place.
I stayed in Seoul and Busan and Busan is my favorite place in Korea so far - so if to go to Korea, I would recommend to visit Busan, or to stay there a little bit longer.
Busan is quite close to Seoul though, just a few hours by train (around 4 hours). When I was traveling by train, I've got the ticket Busan-Seoul-Busan for less than 100$. While the airplane ticket was around 80$ one way.
The train station is located near city center, so it's quite convenient.
I arrived in the middle of December, it was a beautiful time, autumn with colorful trees, not so cold, around 12 degrees, quite comfortable for me and all this Christmas installations improved my Christmas mood.
Let's start with a city view (from Lotte Hotel).