I have now visited all three WHS listed dolmen sites in Korea and consider the Gochang site to be the most interesting. There I saw a whole mountainside dotted with 128 dolmen of several different styles. Altogether there are around 2000 dolmen on this district. The visitor centre at the dolmen site is served by a bus from Gochang town, which in turn has bus connections with Jongeup and Janseong, both stations on the Mokpo railway line.
The Hwasun dolmen I reached from Neungju railway station, and the Ganghwa site by bus from the Sincheon bus station in Seoul.