During the Joseon Dynasty, what are now Bonghwa and Yongmabong Peak and the Manguri Cemetery were considered part of Achasan Mountain. Twenty bastions were discovered along Achasan Mountain that were originally estimated to date back to the Three Kingdoms Era. Further research indicated that some of the remains were actually part of a military fortress built during the Goguryeo Era. In light of these findings, it was officially designated a Historic Site No. 455 (2004).