Beijing: Archaeologists in China have uncovered a vast network of underground tunnels beneath an ancient stone city in Inner Mongolia, offering a rare glimpse into how people lived, defended themselves and organised their society more than 4,000 years ago.
The discovery was made at the Houchengzui Stone City, a prehistoric settlement believed to date back to the Longshan cultural period. Researchers say the site is one of the largest ancient stone cities ever found in northern China and may reshape historical understanding about the sophistication of early Chinese civilisation.
The underground tunnels, hidden beneath layers of earth for thousands of years, were recently mapped through ongoing excavation work carried out by Chinese archaeological teams. Experts believe the tunnels formed part of a carefully designed defence system built to protect the city from attacks and external threats.
The ancient settlement covers nearly 1.38 million square metres and includes massive stone walls, terraces, trenches, moats and gate structures. Archaeologists say the newly discovered tunnels connected different parts of the city and may have allowed people to move safely underground during times of danger.
Researchers are still studying the exact purpose of the passages, but many believe they may have been used as escape routes, military pathways or hidden communication corridors. Some experts also suspect the tunnels could have served as storage spaces for food, weapons or other important supplies during conflicts.
What has surprised historians most is the level of engineering involved in the construction. The tunnel system appears to have been planned with remarkable precision, suggesting that the people who built the city possessed advanced knowledge of architecture, defence and urban planning much earlier than previously believed.
The Houchengzui site has been under investigation since 2005, but the scale of the underground network only became clear after recent excavations and modern mapping studies. Archaeologists used improved surveying methods and careful digging techniques to trace the buried pathways beneath the ruins.
The findings are drawing attention not only in China but also among international historians and archaeologists. For many years, scholars believed that highly organised cities and complex defence systems in China emerged mainly during later dynasties. However, discoveries at Houchengzui now suggest that advanced social structures and strategic planning existed in prehistoric northern China more than four millennia ago.
Experts have compared the discovery to other important ancient Chinese archaeological sites, including the Liangzhu civilisation near present day Hangzhou. Liangzhu is known for its sophisticated water management systems and urban planning and has already changed global understanding of early Chinese civilisation.
The newly discovered tunnel network is being viewed as another example of how ancient communities in China developed large scale engineering projects long before modern technology existed.
Researchers believe there may still be many hidden structures buried beneath the site. Excavation work is continuing, and archaeologists hope future discoveries could reveal tools, artefacts or human remains that may explain more about the people who once lived there.
The discovery has also sparked public fascination across social media in China, with many people expressing amazement that such an advanced underground system could survive unnoticed for thousands of years.
For archaeologists, the tunnels represent more than just hidden passageways beneath an ancient city. They offer a direct connection to a forgotten civilisation and provide valuable clues about how early humans adapted to danger, organised communities and built complex societies long before written historical records began.