The Longquan Mansion site in Shangjing of the Bohai Kingdom, close to jingpo Lake, is the remains of the capital city of the "Haidong Kingdom". It is located in Bohai Town, Ning'an City, less than 20 kilometers away from jingpo Lake. It imitates the layout of Chang'an City in the Tang Dynasty. It is an important ancient civilization site in Northeast Asia. In 2021, it was selected as one of the "Top 100 Archaeological Discoveries in the Nation" in 2021. The Bohai Kingdom, dominated by Sumo Mohe, lasted for 229 years from 698 to 926. The ruins of the Bohai Kingdom include palace ruins, stone lanterns, large stone Buddhas and other relics, which quietly tell the glory of the ancient country. It is the link between the natural beauty of jingpo Lake and the thousand-year cultural context of the Northeast.

Mohe embroidery is an intangible cultural heritage skill inherited by the Bohai Kingdom for thousands of years. It originated in the Bohai Kingdom period. As a "national treasure" at that time, it is the crystallization of the wisdom of the Sumo Mohe people. It was included in the national intangible cultural heritage list in 2014. It uses Northeastern unique tussah silk as raw material, adopts an improved triangular needle method, is superimposed layer by layer, and the silk is mixed with color. It has a strong three-dimensional effect and is known as "the oil painting in embroidery." Its style is majestic and majestic, retaining the roughness and simplicity of the Mohe people while integrating the essence of Central Plains embroidery. The theme covers Northeastern customs and folk customs. Now it has become a cultural symbol that carries Bohai civilization and highlights regional characteristics. Together with the Bohai ruins, it tells the millennium cultural context around jingpo Lake.