On a hillside in Fujian province's Mount Wuyi, the grass still grows over two dark-red scars in the earth. They are all that remain of a fire that burned out 3,000 years ago. But what that fire produced and where those products ended up, archaeologists say, have rewritten a chapter of Chinese ceramic history.

This is the only known kiln site in China from the early-to-middle Western Zhou period (c. 11th century-771 BC), and the best-preserved "living fossil" of proto-porcelain production from the pre-Qin era (before 221 BC).

Proto-porcelain is the precursor to mature porcelain. Fired at temperatures above 1,100 C, hundreds of degrees hotter than ordinary pottery, it was coated with a glassy glaze. Differences in raw materials and firing stability set it apart from true porcelain, experts explain.

For decades, the chronological sequence of proto-porcelain in China contained a puzzling gap. More than 100 pre-Qin kiln sites have been discovered across the country, concentrated mainly in the north of East China's Zhejiang province, spanning the Xia (c. 21st century-16th century BC) and Shang (c. 16th century-11th century BC) dynasties, the late Western Zhou, and the Spring and Autumn (770-476 BC) and Warring States (475-221 BC) periods.

But the early-to-middle Western Zhou, a crucial three-century period around 3,000 years ago, remained a blank spot.

"It was as if a complete history of ceramics was missing its central chapter," says Zheng Jianming, a professor of archaeology at the Shanghai-based Fudan University.

The gap also fueled a long-running academic debate: did protoporcelain originate in northern or southern China?

That missing chapter has now been found in the bamboo-shaded hills of Mount Wuyi. In 2025, archaeologists launched a new excavation of Kiln No 1 at the Zhulinkeng site. Radiocarbon dating confirmed the kilns were active around 3,000 years ago, squarely in the early-to-middle Western Zhou period.