Introduction to the Yellow River Iron Ox: There are about 6,700 hectares of green forest on the banks of the Yellow River. The natural scenery is beautiful, but the most famous ones are the 4 iron oxen and 4 iron men that reappeared in the world in August 1988. In 724 AD, Emperor Xuanzong of the Tang Dynasty Li Longji issued an edict to change the original bamboo cable Pujin pontoon bridge into an iron cable chain pontoon bridge in what is now Yongji County, and cast four large iron oxen and four large iron men on both sides of the Yellow River. After experiencing floods, diversions and other changes, the Iron Ox and the Iron Man remain rust-free, smooth and complete, and are rare in real numbers.