The underground roadway in front of the Yeouido National Assembly was completed on September 30, 1977 as a road facility installed at the 17-27 Yeouido-dong, Yeongdeungpo-gu, The tunnel is 21m in width and 150m in extension. The retaining wall is 1.0 ~ 5.5m in height and 375m in extension, total length is 525m.
