Anju Castle

The Anju Castle is a military fortress built during the Goguryeo kingdom, later rebuilt during Joseon era [1]. It is located in Anju City, South Phyongan Province, North Korea [1]. The fortress consists of three parts, all built at different periods; an inner fort, an outer fort and a new fort [1]. The inner fort dates from the Goguryeo period; it has walls along the ridge of the Kadu range on the shore of the Chongchon River [1]. These walls were 7–8 metres high from the level ground and 4–5 metres on the slope of the hills, 6500 metres long [1]. The outer fort was built during Joseon period; it is 3 650 metres long [1]. The new fort is over 550 metres long and was built in the 17th century [1]. The fort was rebuilt several times during the Goryeo and the Joseon periods [1].