Nandaemun at night
NAndaemum in the morning.
I think Nandaemum is different day and night.
Try exploring the different buildings, some sell clothes, some sell food, some sell household stuffs.
If you are looking for clothes that are bigger in size or for older woman, this is the place.
I saw lots of people carting back korean pots and pans.
Just watch out for tourist traps as some things tend to overpriced, and if you are interested in buying seaweed, just go to the supermarket. It is much much cheaper.
Dongdaemum. The party starts at night. The shops here open till 4-5.am. I find some of the price around the same as ehwa university shopping area. Maybe is more for wholesale.
However, there are shops selling clothes and accessories for both guys and girls. Skinfood and Missha and other shops can be found here.