Lei Chi is the name of a lake, which was originally located in the south of Wangjiang County. How is the thunder pool formed? It is made up of thunder and water. According to historical records, the water in Gu Lei flows eastward when it passes through this place where the thunder pool is now formed, and it collects here. Later, with more and more Gu Lei water flowing to this place, the ancient mineral water here is also accumulating and gradually forming a pool, so this lake is called a mine pool.
The origin of the thunder pool has a long history. Although it is impossible to know the specific time of the formation of the thunder pool, according to historical records: "Meng Zong was appointed as the supervisor of the thunder pool, and he was the mother's instrument, and the mother did not accept it." Who is Meng Zong? He was an official during the Three Kingdoms period. In other words, the latest time for the emergence of the cross-country was in the Three Kingdoms period, at least at that time, the cross-country had already existed in the world.
There is also a legendary allusion to the thousand-year-old proverb "Don't dare to cross the line". It happened in the Eastern Jin Dynasty, when Yu Liang served as the secretariat. He holds the power of the court. In order to stabilize the frontier, he arranged for Wen Qiao, a trusted minister, to be an official in Jiangzhou to strengthen the stability of the frontier. Later, Yu Liang heard that the Soviet army, the prefect of Liyang, was struggling with various forces in an attempt to occupy Jiankang and seize the throne.
Finally, Su Jun rebelled, but Yu Liang thought he was not afraid, so he sent a letter to Wen Qiao: "I am worried about the West, and I have not crossed the line." In other words, he thinks that the western border guards are more important than the Soviet rebellion, so he will not let Wenqiao cross the border and lead troops to support Kyoto. Finally, the Soviet army has been attacking Jiankang, and Kyoto is in jeopardy. Yu Liang united with Wenqiao to defeat the Soviet rebels, and this proverb spread.