The origin of blue mountain place names

Blue Mountain is located on the southern border of Hunan, bordering Lianzhou City, Guangdong Province in the south. During the Spring and Autumn Period and the Warring States Period, it belonged to Chu, and Nanping County was built here in the fifth year of Emperor Gaozu (202 BC). In the first year of Tianbao in Xuanzong of the Tang Dynasty (AD 742), it was renamed Blue Mountain because of its "overlapping mountains and green sky", which has been passed down to this day.