After construction of the Walled Square of Chu many more ‘new era’ Long Walls were built from the late fourth century B.C..
Three very early text records provide clues on when the first changcheng, or long wall, may have begun.
Legend has it that during the Xia Dynasty (c. 2070-1600 B.C.), a sage named Gun, father of Yu the Great, built a concentric walled city in which the inner structure defended his son the prince, while the outer one protected the common people.
Visually the Great Walls are diverse in appearance, but most commonly they consist of rammed earth, stone and brick.
The best-preserved part of the Han Great Wall can be found five kilometers west of Yumenguan, and 90 kilometers to the north west of the city of Dunhuang.
