List of fortresses in Korea

Korea has a variety of fortresses, including sanseong (mountain fortress), jinseong (camp fortress), and eupseong (city fortress). == Ancient == Hwando Fortress (위나암성; 尉那巖城) in present-day Wandu Sanggyeong (상경용천부; 上京龍泉府) in present-day Ning'an, then capital of Balhae Hwangryong Fortress (황룡산성; 皇龍山城) Achasanseong (아차산성; 阿且山城) Namhansanseong (남한산성; 南漢山城) Busosanseong Fortress, Buyeo (부여 부소산성; 扶餘 扶蘇山城) in present-day Buyeo, then third capital of Baekje.

Source: Wikipedia — List of fortresses in Korea (CC BY-SA 4.0)