Hwangryong Fortress
North Korea
Hwangryong Fortress (Hanja) is a stone fortress of Goguryeo located in what is now Ryonggang county, Nampo in North Korea. It is designated as "No.37 National Treasure of North Korea". It is about 10-11 metres high, 6-8 metres in width and has a 6.6 kilometre circumference.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).