Shangjing Longquanfu (Chinese: 上京龍泉府) or Sanggyeong Yongcheonbu (Korean: 상경용천부), also known as Shangjing/Sanggyeong (上京, 상경), Huhan/Holhan Fortress (忽汗城, 홀한성), is an archaeological site in Ning'an, Heilongjiang, China.
[1] Shangjing was modelled after Chang'an, the capital of the Tang dynasty.
[1] Balhae was founded at the Dongmo Mountain by Dae Jo-yeong.
However, Balhae set up five capitals to rule its territories, and also transferred the main seat of the government several times because stabilizing and strengthening central rule over various ethnic tribes in its realm, which was expanded temporarily.
In 756, during the reign of King Mun, Shangjing Longquanfu was established as the permanent capital near Lake Jingpo, south of today's Ning'an, Heilongjiang, China.