建立了延庆县旅游生态环境质量评价体系。

Tourism eco-environmental quality evaluation system of Yanqing was established.

它坐落在延庆县北部一条幽静的峡谷中，是由一支不见史志记载的古代先民在陡峭崖壁上开凿的石窟居室。

It is located in a quiet valley in the north of Yanqing County. It is said that, ancestors cut in the steep cliff and built the cutting room caves, which are 147 rooms in total.