Introduction to the mounds: Formed by hundreds of millions of years of wind, rain, water and sunshine. They are arranged parallel to the wind direction and alternately, like the ruins of ancient castles, standing out in the Gobi. They range from square to round, mostly with orifices, and are more than ten meters high, with the tallest one being more than thirty meters high. The earth mounds connected together are like the fortresses in the city wall, and the mound-walled caves are like Buddhist niches in different shapes. The larger circles are like palace walls; the middle circles are like granary seats; there are even pavilions and pavilions, temples and pagodas. Some of the square shapes look like ancient beacons, and some look like military parade points. Thousands of mounds, thousands of shapes; hundreds of mounds, hundreds of styles, are dizzying for people to see and allow their imagination to run wild. On the top of the mound, some look like human faces, some stand like apes; there are also eagles carved by the wind, and bears carved by the rain.