For archaeologists who are dedicated to decoding the early stages of how a nation was formed in China, looking for clues of the Xia Dynasty (c. 21st century-16th century BC) has been a focal point.

As the first hereditary dynasty with a central kingship recorded in Chinese history, Xia has not yielded any written documentation of its time.

Nonetheless, continuous excavations on the massive Erlitou Site in Luoyang, Central China's Henan province, in the past decades have edged toward unwrapping the long-awaited answer for where the Xia capital was. Unearthed ritual relics and architectural ruins there reveal an aura of kings, and its location, time, and landscape echo historical recordings.

Now, new findings on another key site, more than 200 kilometers to the south of Erlitou, may further enrich people's understanding on this foundational dynasty that shaped the course of social development in ancient China.

In Fangcheng county, Nanyang, also in Henan province, the Baliqiao Site spreads across over 1.35 square kilometers, nearly half of the area of the Erlitou Site that has survived to date.

Since 2022, scholars from the Henan Provincial Institute of Cultural Heritage and Archaeology and Nanyang Institute for the Preservation of Cultural Heritage have conducted systematic excavations of the Baliqiao Site.

According to Wu Zhijiang, an associate researcher with the Henan provincial institute, some key findings of urban infrastructure will help identify a high-level settlement that was inhabited around 1700 to 1600 BC, almost perfectly matching the time span of the Erlitou Site.

Rammed earthen foundations and city walls, roads, moats as well as other facilities jointly portray a city that may have enjoyed the status of regional core, Wu notes.

The length of a large-scale architectural foundation reached 50 meters, indicating a key building. Archaeologists named it the No 1 foundation ruins. Spanning 12 meters from south to north and 31 meters east to west, this 372-square-meter house inspires researchers to imagine its exceptional role in the city.

"It was found to be surrounded by corridors, and it also had a courtyard," Wu says, as he excitedly recalls the discovery.

An approximately 190-meter-long southern section of city wall was found, for instance. The main part of the wall was 4.5 to 5 meters wide, and the surviving part was 1.5 meters high.

Some unearthed artifacts echo previous findings on Erlitou, which may further suggest links between the two sites.

For example, turquoise and bronze wares are two types of signature objects of the Erlitou Site — the bronze turquoise dragon-shaped artifact and bronze bells reveal a highly developed ritual system. In Baliqiao, researchers also found related clues.

Baliqiao has yielded 63 turquoise objects. Most of them are slices but some are also decorative beads.

"The presence of a small amount of turquoise waste indicates the possibility of a workshop at the site," Wu explains.

In the excavation of a section of wall, a significant amount of fired clay blocks with bronze residue was found. Preliminary observations suggest that these blocks may be remnants of furnace walls.

"The bronze residue, including lead-tin-copper alloy, indicates that a workshop for smelting and casting bronze artifacts probably existed at the site," Wu says.

Other than that, almost all the types of pottery unearthed at the Erlitou Site can also be found on Baliqiao. Wu and his colleagues have also discovered similar grid-shaped urban layout at both places.

"All highlight the high social productivity and status of the Baliqiao Site, making it an important settlement in the southern region of the Xia territory," Wu says.

He speculates that the site was used to fortify the safety of the capital city and ensure the logistics of crucial resources, such as copper ore and turquoise.

"If we want to understand Erlitou, it's not enough to only see Erlitou," says Xu Lianggao, a researcher with the Institute of Archaeology at the Chinese Academy of Social Sciences.

"We need to study settlements of different tiers other than a capital city," he says. "Baliqiao Site, which is at the crossroads of cultural communications between northern and southern parts of China, just provided a key reference."

In the south of Henan province, recent studies on a series of sites from the Erlitou era have gradually portrayed a panorama of society — barns, military fortifications, and stone-processing plants.

Dai Xiangming, a professor at the Capital Normal University, considers that new findings on Baliqiao help to offer an example of national governance in its early stages, and has a huge potential as only a small portion of the site has been unveiled.

"It's still premature to come to conclusions," Dai says.

"We may unearth more significant findings after we make clear the boundaries of the site."