Archaeologists investigating an ancient city in south-west China have uncovered evidence of a major Han Dynasty urban centre, including fortified walls, streets, workshops and what researchers believe could be the only known Han-era “water gateway” yet discovered in the country.
The discoveries come from the Chengba archaeological site in Quxian County, eastern Sichuan Province, where researchers have been piecing together the remains of a settlement that played an important role in the region for centuries.
Covering approximately 50,000 square metres, the Han Dynasty city was surrounded by a gated wall measuring about 725 metres in circumference, as well as a moat.
Inside, archaeologists have identified streets and building foundations, while surrounding areas have revealed evidence of a cemetery, pottery production and a riverside dock.
Researchers believe the city walls were first constructed during the early Western Han Dynasty, between 202 and 141 BC, before undergoing several phases of repair.
The discovery is particularly significant because Chengba is the first Han Dynasty city site identified in eastern Sichuan. Other known Han urban sites in the province are predominantly concentrated around the Chengdu Plain.
Could this be the lost city of Dangqu?
Evidence recovered during excavations suggests Chengba could be the location of an ancient city known from historical records.
Bronze objects dating to the Warring States Period have led researchers to associate the settlement’s earlier phase with ancient “Cong City”.
During the Han Dynasty, however, historical sources record the establishment of Dangqu County as part of Ba Commandery.
A particularly important clue has come from large numbers of roof tiles discovered at Chengba bearing inscriptions containing the characters for “Dangqu”.
When combined with historical descriptions of the county’s probable location, researchers say the evidence makes it “very likely” that Chengba was the ancient Dangqu City of the Western Han Dynasty.
Its location may also explain why the settlement became important.
Chengba sits on the eastern bank of the Qujiang River, which flows into the Jialing River and ultimately the Yangtze. To the north, the Micang Pass provided a route through the Daba Mountains towards China’s Central Plains.
Despite the surrounding terrain making overland travel difficult, the combination of river transport and mountain passages placed the city at an important crossroads connecting different regions.
Possible Han Dynasty ‘water gateway’
One of the most intriguing discoveries lies beside the Qujiang River, north-west of the ancient city.
Archaeologists have identified what they describe as a dock area. Based on its position and information contained on bamboo slips recovered there, researchers have proposed that it functioned as a combined land and water gateway.
Officials may have used the site to inspect travellers and boats while regulating resources and the movement of traded goods.
If that interpretation is correct, the researchers say it would represent the only Han Dynasty water gateway so far discovered in China.
The bamboo documents found at Chengba are themselves an important discovery.
Their contents deal with subjects including finance, judicial affairs and education, covering areas such as calligraphy, literature and arithmetic.
Some also contain information relating to household registration, a category of Han Dynasty bamboo document rarely recovered in China.
Researchers say the texts could therefore provide valuable evidence about local government, education, everyday life and the household registration system during the Western Han period.
More than 20,000 pieces of iron-smelting debris
Chengba was not only an administrative and trading centre. Excavations have also revealed extensive evidence of iron production.
More than 20,000 fragments of slag, furnace lining and tuyeres — nozzles used to force air into furnaces — have been recovered from the site.
Radiocarbon dating indicates that smelting continued from the late Western Han Dynasty into the middle of the Eastern Han Dynasty.
The scale of the remains makes Chengba an important source of evidence for understanding how iron was produced and circulated in eastern Sichuan during the Han period.
Other finds include bronze objects, inscribed roof tiles and a bronze musical instrument.
Bronze ritual vessels and weapons dating from the Warring States Period indicate that the settlement was already an important centre of activity when the region formed part of the ancient Ba state.
A city occupied for centuries
Archaeological evidence suggests Chengba remained an important urban settlement from the late Warring States Period through the Qin and Han dynasties, spanning several centuries from roughly the fourth century BC onwards.
Its position between river routes and mountain passages appears to have allowed the settlement to serve as a communications hub between China’s Central Plains and the middle reaches of the Yangtze River.
Researchers say the identification of distinct residential, industrial, administrative and other functional areas could help reveal how Han Dynasty county-level cities were organised and governed.
Future archaeological work will seek to identify additional areas of the settlement and establish a more detailed chronology of how Chengba developed.
The findings could ultimately provide archaeologists with a much clearer picture of urban life, administration, industry and trade in a part of ancient China where archaeological evidence from the period has previously been comparatively scarce.
Sources : Antiquity : Sun T, Liu F, Chen W, Li Y, Li Y. Chengba: the Dangqu City of the Han Dynasty in south-west China. Antiquity. 2025;99(404):e14. doi:10.15184/aqy.2024.187
