Gungnaeseong or Guonei was the capital of the ancient Korean kingdom of Goguryeo, which was located in Manchuria and the Korean Peninsula. The perimeter of its outer fortress measures 2,686m. 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. 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.