Great Wall of Qi

The Great Wall of Qi (simplified Chinese: 齐长城; traditional Chinese: 齊長城; pinyin: Qí Chángchéng) is the oldest existing Great Wall in China.

[3] The wall stretches from Guangli village of today's Changqing District, Jinan, running across the mountain ridges of central Shandong Province to the Yellow Sea in the present-day city of Qingdao.

The earliest possible date is during the reign of Lord Huan of Qi (r. 685–643 BC) as mentioned in the Guanzi's "Qing zhong D" (輕重丁) chapter.

However, the "Qing zhong" chapters of the Guanzi were in all likelihood composed no earlier than the Warring States period instead of the 7th century BCE work they purport to be, and thus could not be seen as a reliable historical source for the Spring and Autumn period centuries removed.

The Zuo zhuan itself, however, never used the term "great wall" (長城 changcheng) or referred to other fortifications along Qi's southern border, throwing doubts into this identification.