Azernews.Az

By Alimat Aliyeva

Archaeologists have discovered an extensive underground labyrinth system dating back approximately 4,000–4,500 years beneath the ruins of the ancient stone city of Houchengzui in northern China, AzerNEWS reports.

The discovery was reported on May 7 by The Times of India, citing research sources involved in the excavation.

The site is located in the Inner Mongolia Autonomous Region. According to experts, the tunnel network was constructed around 4,300–4,500 years ago beneath one of the most heavily fortified settlements of its time. Researchers from the Institute of Archaeology of the Chinese Academy of Social Sciences believe the underground passages were likely used for defensive purposes, as well as for the concealed movement of people within the fortress during times of danger.

In several sections of the tunnels, scientists found traces of primitive stone and bone tools, suggesting that the passages were carved entirely by hand. The archaeological complex itself is situated on the northern bank of the Hunhe River in Qingshuihe County. The ancient city covered an area of approximately 1.38 million square meters and had an elliptical layout, stretching about 1,200 meters in length.

Ongoing excavations over the past five years have revealed that the settlement belongs to the Longshan cultural period and had a remarkably sophisticated urban structure. It included inner and outer city zones, gates, defensive walls, and surrounding moats, indicating a high level of social organization for its time.

The tunnel system, located at depths ranging from 1.5 to 6 meters, further highlights the advanced engineering capabilities of its builders. The passage ceilings feature a vaulted architectural style typical of the Longshan culture, suggesting intentional and carefully planned construction techniques.

Some archaeologists speculate that the tunnels may have served more than just military purposes. There is a possibility that they were also used for ritual activities or as hidden storage areas for grain and valuables during periods of conflict. If confirmed, this would indicate that the underground system played a much more complex role in daily life than previously assumed.