F&E Winter in Seoul, help needed!!

Hi guys,

I have plans of travelling F%26amp;E to Seoul from X%26#39;mas day to the 4th Jan 09, It%26#39;s my 2nd time to Korea, but there were some places missed out the 1st time.

How should I plan if the following places I would like to visit, where other places recommended?

Would want to visit:

COEX mall / 63 city / Hangang River / Insadong / Samsung Plaza

I%26#39;m staying in Myeongdong Guesthouse.

Pls recommend some interesting places where I can go, for X%26#39;mas and New Year Eve %26amp; Day..

Thanks a lot.