The ruins of a prehistoric underpass have been discovered in northern China's Inner Mongolia Autonomous Region.
An underpass located in the site of an ancient stone city in present-day Qingshuihe County, Inner Mongolia, was discovered along with more than 20 ruins, including a city gate. , city walls, building foundations, tombs, jade, pottery and bones. The site of the stone city with an area of about 1.38 million square meters. meters belongs to the Longshan culture, a Late Neolithic civilization in the middle and lower reaches of the Yellow River.
The long and narrow passage is 5−6 meters underground and has a width of 1 to 3 meters with a height of about 2 meters with arched top. It connects the territories inside and outside the ancient city, as well as its two trenches.
During the excavations, traces of working tools were found, and its trampled surface was partially destroyed by fire and acquired bright red colors. According to the researchers, these discoveries are of significant value for the study of prehistoric culture and the origins of civilization in the northern regions of China.