I will post a serie of articles on what to do / what to see in Seoul and in Korea. For the 1st article I will write about something that I consider worth to see in Seoul, but still quite unknown : The banpo Bridge (반포대교).
Indeed usually tourists don't know much about it, and don't go to see it. Even many of my Korean friends haven't seen it yet! You would miss something if you leave Korea before getting there.
As a foreigner, one thing that surprised me when I first visited Seoul is that I couln't find and postcard or souvenirs to send to my family / friends.
Even when visiting the tourists spots, there was no postcard there! Then my korean friends let me know a street in Seoul dedicated to that : The place you need to go is named Insadong (인사동).