Located under World Trade Center, COEX mall is the biggest underground shopping mall in Seoul. Personally, I didn´t like this place very much: too many people, too many shops, too many restaurants and too many advertising everywhere (all over the walls, floor, even on the ceiling.) However, I went there more than 5 times a week, as my work was nearby. It's one of the best place to kill time: they have a multiplex cinema (16 screens), aquarium, huge book shop, and thousands of little shops.
books books and even more books. great shop for everything Korean but also a huge selection of local books and different language books. GReat spot for a coffee and some serious people watching. Nice interiors and easy to get lost in here too
With over 20 buildings and over 5,000 stores that sell everything electronic this is the best place in Seoul to buy that gadget, tool or computer. Great deals to be had and you can barter if you want, they kinda like that. Every gismo and gadget know to man is here, be prepared for the onslaught :))
Insa-dong is a narrow street lined with antique stores, art galleries and secondhand bookstores. Find bargains on calligraphy, paintings, and a huge variety of implements and articles from Korea's past, some small enough to carry home for friends or for keeps !!! Even if you don't buy anything its a great way to see the history of a city & country !!
Every Saturday afternoon, there's a special market at the playground right in front of Hong-ik Univ. Young artists and designers bring their 'usable' art pieces to meet people who are looking for non-labled special products. Some artists just start creating customized things after talking with their customers.
Young musicians also participate in the market, by playing music at the other part of the playground. If you want to meet creative people and special product, don't miss this place.