Originally Posted by
guwinster
There is an express commuter rail style subway that runs from both Incheon and Gimpo Airports to Seoul Station. Seoul Station is maybe a 5-10 minute walk from the Millennium Hilton. The subway costs something like 3-3.50 USD. If you get disoriented at Seoul Station, a taxi from Seoul Station to the hotel would be another 3 USD (the base fare).
I highly recommend finding the Hangeul (Korean) script for your hotel and writing it on an index card. That way you can just give it to a taxi driver if you ever get lost. Taxis within the Seoul's downtown core are never more than $20 and often a lot less.
The Millennium Hilton is know to Seoul cabbies as "Namsan Hilton"