Charcteristics Study on Ancient Fortress Relics in Busan and Tasks
There are ancient castles built in the eras from Silla to Goryeo such as Bae Mountain Fortress (盃山城), Gijang Mountain Fortress (機張山城), Mang-Mi-Dong Fortress (望美洞城) and Gyo-Ri Fortress (校里城) in Busan; as they are in accordance with the center of Dongrae-gun (東萊郡) and Gijang-hyun (機張縣) in Samguksagi Jiriji (三國史記地理志) from a spatial and temporal perspective (時空間的), this study assumed that the characteristics had something to do with Chi-So Fortresses (治所城) of gun and hyun (郡縣).
During the Silla Dynasty, Busan was considered a strategic city for marine defense (海防). It is presumed that gun and hyun system (郡縣制度) was established and fortresses were started to be built during the period of King Shinmun (神文王代) in the city: Bae Mountain Fortress in Yeonje-gun and Gijang Mountain Fortress in Gijang-gun. These were constructed at the top of mountains in Temoe type or Pogok type and in coursed masonry with rectangular stones; inside them are affiliated structures including well areas for revetment, collecting wells and building sites. They are assumed to be made in the 7th century since the excavation of relics of cups with short legs, which were popular after the late 6th century. Given that they share the same characteristics as mountain fortresses in Gyeongsangnam-do from the Silla Dynasty such as Hwa-Wang Mountain Fortress (昌寧 火旺山城) in Changnyeong, Dun-Deok-Gi Fortress (巨濟 屯德岐城) in Geoje, Georyu Mountain Fortress (固城 巨流山城) in Goseong, Sung Mountain Fortress (咸安 城山城) in Haman, Gohyun Mountain Fortress (南海 古縣山城) in Namhae, Bun Mountain Fortress (金海 盆山城) in Gimhae, etc., and most cognize them as Chi-So fortresses (治所城) in gun and hyun (郡縣) in the Silla Dynasty, Bae Mountain Fortress and Gijang Mountain Fortress can also be considered Chi-So Fortresses of Dongrae-gun and Gijang-hyun. Moreover, based on the recent study that mountain fortresses from the Silla Dynasty located in Gyeongsangnam-do formed separated castles or cities at the foot of the mountains or valleys, their relationships between Bae Mountain Fortress and Mangmi-dong Fortress and Gijang Mountain Fortress and Gyori Fortress in Busan can be considered the same.Although Mangmi-dong Fortress and Gyori Fortress are fortresses, relics excavated inside them at the beginning showed little difference from those discovered in mountain fortresses; which implies that they were built in the same era of the Silla Dynasty. Certainly, it should not be overlooked that a lot of relics uncovered from fortresses continued to the Goryeo Dynasty. Thus, they are considered to have typical features of gun and hyun fortresses (Chi-So Fortresses) in the Silla Dynasty. At that time in Busan, as for classification of locations for Chi-So, gun and hyun fortresses with distinct characteristics of Gwan-Bang Fortress (關防城) were constructed to protect changed regions against Japan despite the unification of Silla; later, as the relationship between the two countries came to a state of lull, they are considered to have been moved to flatlands.