The Seokmosan area around Rajetongmun is thought to have lain near the Baekje–Silla frontier. The present tunnel, however, is not a Three Kingdoms gate. Muju County says it was cut through rock during the Japanese colonial period for purposes including gold-mine development.
Today it is the first of the 33 Gucheondong scenic sites and a national geopark geosite. Separating the old frontier from the tunnel’s modern construction makes the familiar story more accurate.