I visited the dolmen site in Ganghwa Island in Jan. 1, 2010. It is an ideal day trip for those based in Seoul. The earliest bus from Sinchon station is at 5:40 a.m. and the trip will take about an hour and a half.

There are many things to see in Ganghwa. Apart from the dolmen sites, I also visited fortresses (overlooking the sea) and a palace. Be sure to check the bus schedule as they are quite few. It was cold when I went and waiting for buses going back to the terminal or to other locations in the island took at least 30 mins each time.