Gongsanseong Fortress is a representative ancient fortress from Baekje Dynasty and it protected capital city for 64 years over 5 generations since King Munju transferred the capital from Han River basin during his first year (475) until King Seong transferred the capital again to Boyeo during his 16th year (538). The fortress embracing the valley was made by piling up the soil along the ridge which is at an altitude of 100m and valley.
It was also addressed as Woongjinseong Fortress during Baekje Dynasty, Gongjusanseong Fortress during Goryeo Dynasty, Gongsanseong Fortress after Goryeo Dynasty and Ssangsusanseong Fortress after Injo stayed at the fortress after escaping from insurrection initiated by Igwal in 1624. It was rebuilt during Seonjo and Injio into Stone Fortressas now and history by period can be seen at Gongsanseong Fortress as it was continuously utilized. Fortress was made not to be invaded from outside while having 2 gate towers and hidden gate in the South and North. Gongjuoknyeobongseong Fortress(Chungcheongnam-do monument No. 99) next to Gongsanseong Fortress was made by piling soil and it served as an auxiliary fortress of Gongsanseong Fortress.
It was confirmed by excavation research, Palace site, affiliated facility site and earthen fortress from Baekje Dynasty were found. In addition, Gongsanseong Fortress has beautiful natural environment with Geumgang River on the top of its historical background.
Gongsanseong Fortress has Yeongdongru, Geumseoru, Jinnamru and Gongbukru at cardinal points that lead every direction and Yeongeunsa Temple in the center. Different lifestyle of Baekje can be observed from Gwangbokru or Meyongguksamjangbi memorial stone.
Yeongdongru is one of the 4 gates in Gongsanseong and it is located in the east. Its ground structure was found during excavation research in 1980. The stone was used to support the original gate from both sides and the tower was restored based on the record showing that it was a 2 story building with 3 divided spaces in Gongsanji.
Geumseoru is one of the 4 gates located in the west and only the site was left. It was restored in 1993 after being used as a gateway. According to Gongsanji, it was the same building as east gate having 2 stories with 3 divided space in the front and 1 divided space in the side.
Jinnamru is the south gate of Gongsanseong Fortress and it was rebuilt into stone fortress in Joseon Dynasty and it served as a gateway of Samnam during Joseon Dynasty.
Gongbukru is the north gate of Gongsanseong Fortress and it was built on the site of old Mangbukru. It is a good example of tower construction and it served as a gateway between south and north of the river as it was located in the riverside.
It is located inside of Gongsanseong Fortress and it was established during Joseon Dynasty (1458).
It is historically meaningful as Yeounggyu Daesa gathered monk soldiers and camp trained them to participate in Geumsan battle. It was named as Yeoungeunsa Temple from the legend that mountain god helped people to expel Japanese invaders.