Introduction to Maohaiqiang: Maohaiqiang, also known as gable wall, is a stone wall more than 1,000 meters long that was built with stones by local villager Cao Shuangyin for more than half a century. This wall not only has the important function of fire protection and forest protection, but also brings spiritual inspiration to people. The album was reported in the large-scale documentary series of Henan Metropolis Channel - "Beautiful Henan", which was deeply touching. Cao Shuangyin's nickname is Cao Maohai, so everyone affectionately calls it "Maohai Wall".