Where are the frontier fortresses in the Tang Dynasty frontier fortress poems?

1. Yinshan Mountain: In today's Inner Mongolia Autonomous Region, it was often relied on to resist the southern invasion of the Xiongnu in ancient times. (Wang Changling’s Exodus)

2. Snow Mountain: Qilian Mountain in Gansu Province. (Wang Changling’s military journey)

3·Qinghai: Qinghai Lake. (Wang Changling’s military journey)

4. Loulan: the name of the country in the Western Regions of the Han Dynasty.

(Wang Changling’s military journey)

5· West of Guanyang Pass in Yumen, Gansu and east of Congling, today’s north and south territory of the mountain

6·Shanhaiguan, the Great Wall