Tiantian Lake is also called Dadi'ao. It is said that there are eleven levels of land in this place and the geomantic omen is strange, hence the name. Later, in 1965, a huge artificial reservoir covering an area of ??more than 8,000 acres and a total storage capacity of more than 100 million cubic meters was built and listed separately. It was connected to the main peak of Tiantangzhai and the water from the surrounding mountains, so it was named Tiantang Lake.