Although many people believe that China's Great Wall is a single continuous structure, a Chinese archaeologist has stated that the wall actually features multiple parallel walls near several of its sections.
Surveys of several sections of the Great Wall have uncovered sections featuring two to three smaller walls built parallel to the main wall, smashing the preexisting idea that the wall was built as a single continuous extension, according to Duan Jingbo, the director of a surveying team in northwest China's Shaanxi Province.
Duan, who is also a professor at Shaanxi's Northwest University, said that a section of the wall located in Shaanxi is actually composed of two parallel walls. This type of construction allowed military leaders to garrison troops more effectively, increasing the defensive power of the wall, according to the professor.
Duan said that sections of the Great Wall located in other regions in China feature similar fortifications.
The government started surveying the Great Wall more intensively in 2006, aiming to investigate the overall condition of the wall.
The Great Wall was originally built in the Warring States Period (475 B.C. - 206 B.C.) to defend China against nomadic tribes. Sections of the wall that were destroyed during that period were rebuilt during later periods, including the Ming Dynasty (1368-1644).