jonhoram, take Korean Air Limousine (line No. 1) from ICN. It would take roughly an hour from the airport to Westin. I think it is KRW 13,000 one way. If you fly Korean Air, I think that you can get discount (Ask flight attendants)

dtsm, Jeolla is provinces (North and South), and located southwest part of Korean peninusular. Gwangju is the biggest city in Jeolla.
Yonsusan is a chain restuarants. It has multiple locations. I believe there is one at Seoul Finance Center.