After the Yongding River moved south, it left a Yuan Ye and a pond with an island named Yaoyu in the water. The terrain is very similar to the pattern of "one pool and three mountains", so it has become a treasure trove of geomantic omen for the royal family in past dynasties.
In 938 AD, during Lu Ye's Deguang years, Emperor Taizong of Liao established Yanjing as its capital, and Yao Yu Palace was established in Bailiantan in the northeast of the city. Due to the accumulation of soil in the lake, an island in the water has gradually formed, which is called "pebble".
According to Liao history:
There are pavilions on the top of the west city, Yanjiao Tower, Fangshi and Guan Jing in the northeast corner, and there are countless books.
The Tu Ping Classic of Wu Hongbei records that Qionghua Island was Yaoyu in Liao Dynasty, which can prove the existence of Yao Yu Palace.