According to Xinhua, based on more thorough image analysis and field trips to the Great Wall, the team found that each secret door was designed to be compatible with each local’s topography. According to experts, these secret passages are for scouts to pass through, while some are built as communication channels between the inside and outside of the Great Wall or for trade. trade in ancient times.

According to some historical documents from the Ming Dynasty (1368-1644), nomadic tribes were allowed to use such secret gates to graze their livestock between Qinghai and Hetao, northwest China.

China, an area with abundant water and grass at that time. Zhang Yukun, a professor from Tianjin University who also led the research team, said it was possible because some large secret doors could allow two horses to pass through at the same time in both directions.

High-quality images of secret passages spread throughout the Great Wall. (Photo: Xinhua).

“All of this helps to prove that the Great Wall is not completely closed, but ‘secretly open’,” added Mr. Zhang.

Previously, China had very little research on such secret passages. This new discovery is said to be a step forward in studying the history and structure of the Great Wall.

The most mysterious tunnels in the Great Wall have also been discovered by the research team. These passages were recorded by scholars in the Tang, Song, Ming and Qing dynasties.

Soldiers break through the camouflage wall of a secret passage in the Great Wall. (Photo: Xinhua).

“The side of the secret passage towards the enemy is camouflaged with bricks, while the other side is left empty. The enemy has almost no idea of the location of the passage from the outside, but when the main pass is near If it is attacked, soldiers can break through the gate from the inside, like breaking an eggshell and make a surprise attack. This is a great demonstration of ancient China’s military wisdom,” said Li. Zhe and the research team said.

Qin Shi Huang – The King of China who built the Great Wall of China

The Great Wall, with a total length of more than 20,000km, is a UNESCO World Heritage Site and China’s most popular tourist attraction.