Another striking discovery came in 2024 at Location 5, where archaeologists exposed what they call a "stone tool workshop".

Over 70,000 stone artifacts — waste flakes, rejects and half-finished tools — were concentrated in one area.

"It was as if we could see a craftsman sitting there, constantly chipping away," Wang says.

At the bottom sat a ring of fire-cracked stones, a primitive furnace used for heat-treating stone to improve its workability. It is the first clear facility of its kind from the Paleolithic period in East Asia.

The site is located deep in the mountains. The team commutes daily on rough tracks spanning about 12 kilometers.

"It's the most challenging site I've worked on," says Bai Shijun, a field technician with over 20 years of experience.

For Wang and his team, each answer leads to new questions. When exactly was the first microblade pressed? What prompted the creation of the first ornament?

"In archaeology, exploration truly has no end. I am particularly eager to find that moment when ancient human technology underwent a transformation," he says.

Zhao Rixi contributed to this story.