The Great Wall
The origin of the Great Wall can be traced สืบย้อน to defensive walls erected by various states during the Spring and Autumn and the Warring States periods (around the seventh century BC). After Qinshihuang united the country, he repaired, linked up and extended the walls built by the former states of Qin, Zhao, Yan and others into a huge military defense works which started from Liaodong Peninsula คาบสมุทร in the east and ended at临洮Líntáo (in today's甘肃Gānsù Province) in the west, a distance of more than 5 000 km. This is the world-famous Great Wall. The Wall was repaired and maintained over the course of ในช่วง many dynasties, especially during the Ming Dynasty, when the work continued for some 200 years. The eastern part of the wall was mostly of bricks and stones.