The First Fire Tower of the Great Wall 嘉峪关

7 kilometers south of Jiayuguan(嘉峪关Jiāyùguān) City lies the Great Wall's first fire tower(烽火台Fēnghuŏtái), regarded by some as the world's first frustum(a truncated cone or pyramid; the part that is left when a cone or pyramid is cut by a plane parallel to the base and the apical part is removed), or cut-off pyramid(a polyhedron having a polygonal base and triangular sides with a common vertex). This structure marks the western beginning of the Ming Great Wall.

This frustum was built in the 18th year of the Jiajing Period of the Ming Dynasty (1539). With a flat top, it is a square pyramid, with a length, width, and height of each 14 meters. As the result of water erosion over hundreds of years, some parts have been destroyed. Standing alongside a cliff, the frustum shows its age. To preserve the precious relic, the Jiayuguan city government has built a 30-meter-long arched fortification, which creates a secondary structure and functions as an enclosure. Standing on the tower, visitors can experience the grandeur of an ancient civilization while appreciating the marvelous view in this place.