The Seokmun(石門) battle took place in 672, the biggest change in the early days of the Silla-Tang war(羅唐戰爭). The Seokmun battle just before the occurrence of the Baeksu-seong(白水城) battle took place. It was a battle that Silla(新羅) army and Goguryeo(高句麗) revival army united and fought against the Tang(唐). However, unlike the Seokmun, the location of the Baeksu-seong is not clear. A theory was suggested that the location of the Baeksu-seong is the basin of River Jaeryeong(載寧江) and the basin of River Yeseong(禮成江). The origin of River Seoheung(瑞興江) is Cheon-gok(泉谷), and the name of the Joseon Dynasty of River Seoheung is Yong-cheon(龍泉). And springs and wells are concentrated around River Seoheung. Given these points, the original name of River Seoheung would have been Cheon-gang(泉江). All of the Baeksu-seong(白水城), Baeksu-san(白水山), Cheon-san(泉山), etc. seen in the historical data refer to River Seoheung. It is highly likely that the Baeksu-seong was located in the Bongsan(鳳山) area of the Hwanghae-do(黃海道). The old fortresses in the Bongsan area include Hyuryu-seong(鵂鶹城) and Godang-seong(古唐城), of which Godang-seong, is estimated to be the Baeksu-seong.