山西省大同市，是中国的一个四线城市，我们介绍“悬空寺“时提到的“浑源县“就属于这里。Datong City, Shanxi Province, is a fourth-tier city in China. The "Hunyuan County" mentioned in the introduction of "Xuankong Temple" belongs here. 虽然这个城市的经济不像一线和超一线城市那么发达，但是每年都有世界各地的旅游者、络绎不绝地来到这里。Although the economy of this city is not as developed as the first and super first tier cities, but every year there are tourists from all over the world, an endless stream to come here. 原因很简单：举世闻名的“云冈石窟“就在这个城市。The reason is simple: the world-famous Yungang Grottoes are located in this city.