Photo taken on July 16, 2014 shows a section of ruins of Great Wall constructed during the Ming Dynasty (1368-1644) in Yanchi county of Northwest China's Ningxia Hui autonomous region.

Archaeologists have discovered ruins of the Great Wall along the border of Northwest China's Ningxia Hui autonomous region and Gansu province, dispelling a common belief that there were no sections of the wall in this area.

The remains, nine sections with a total length of more than 10 km, are believed to be part of the Great Wall built during the Qin Dynasty (221 BC-206 BC), according to Zhou Xinghua, former curator of the Museum of Ningxia Hui autonomous region and a Great Wall expert.

The findings, made in March and April by Zhou and other researchers, give historians fresh insight into where the wall was built. "Finally, we're able to see the whole picture of the Qin Great Wall," said Zhou.

Among the ruins, six sections, constructed with stones or loess, stretch about 10 km between Nanchangtan Village of Ningxia and Jingyuan County of Gansu on the southern bank of the Yellow River. Because of flooding and natural degradation, the height of these sections of the Great Wall has been reduced to one to five meters.

The other three loess-made sections are located in Damiao region of Jingyuan county. They are 50 meters long in total and five meters high.

To prevent foreign invaders from crossing the Yellow River when it was frozen, the Qin state, which defeated other powers during the Warring States Period (475-221 BC) and later established the Qin Dynasty, built fortifications along the valley beside the river, according to Zhou.

The Great Wall was listed as a World Cultural Heritage Site by UNESCO in 1987. The central government spent more than 500 million yuan (about 81.6 million U.S. dollars) on protecting the wall during the 11th Five-Year Plan (2006-2010).