"The site provides important clues to decode Nanjing's past and how it developed," Chen says.

Often hailed as the "ancient capital of six dynasties", Nanjing has served as the center of dynasties and kingdoms throughout its rich history. The city was the seat of imperial power of six dynasties ruling the southern China from the 3rd to 6th century. It was also the national capital of a united China from 1368 to 1420 during the Ming Dynasty (1368-1644).

Historians used to estimate that Nanjing was founded in 472 BC, when Gou Jian, the king of the Yue vassal state, built city walls at the southwest corner of the present Zhonghua Gate in Nanjing.

"Although no obvious heritage structure was unearthed, such as a gatehouse and turrets, we discovered clear evidence and clues indicating the reason for the city's construction and its development over thousands of years," Chen says, adding that the city's original site may have been destroyed.

He says building on higher terrain, Changgan ancient city was located at the mouth of the ancient Qinhuai River, which was easy to defend and hard to attack, making it a significant military location.

The latest archaeological findings may reshape the city's history, with its emergence tracing back to more than 3,100 years ago. Wang Wei, director of the Chinese Academy of Social Sciences' Archaeology Department, highlights the discovery as a remarkable archaeological finding in tracing the Nanjing's origins.