Second capital of Goguryeo
Gungnaeseong (Korean: 국내성; Hanja: 國內城) or Guonei (Chinese: 國內) was the capital of the ancient Korean[1] kingdom of Goguryeo, which was located in Manchuria and the Korean Peninsula.[2] The perimeter of its outer fortress measures 2,686m.[3]
It is located in present day Ji'an city, Jilin province, northeast China. Because of its historical importance and exceptional architecture, Gungnae was designated as a UNESCO World Heritage Site in 2004.[4] It is part of the Capital Cities and Tombs of the Ancient Koguryo Kingdom World Heritage Site, together with nearby Hwando Mountain City and the Onyeosan City, in modern northeast China.