Achasan

Achasanseong Fortress is an earthen mountain fortress of the Korean Three Kingdoms period. Originally built by Baekje, it was occupied in turn by each of the Three Kingdoms. It stands on Achasan Mountain, in Gwangjin-gu, Seoul, South Korea, at an altitude of 200 meters above sea level. It has a perimeter of roughly 1 kilometer and an area of about 3375 m².

Achasan is a mountain that sits between the counties of Gwangjin-gu and Guri in South Korea. It has an elevation of 287 m (942 ft).As you walk down towards Mt. Achasan from the summit of Yongmasan, you will find the ruins of a small fort of the Goguryeo era (BC37~AD668) built at a strategic point overlooking the area of Jungnangcheon Stream.

Buramsan is a mountain in South Korea. It sits on the boundary between the district of Nowon-gu in Seoul, the national capital, and the city of Namyangju, in the province of Gyeonggi-do. It has an elevation of 507 m (1,663 ft). It also has a heliport at the second peak (420 m (1,378 ft)) .