Archeologists have discovered the ruins of an ancient city in North China's Inner Mongolia autonomous region, believed to have been built some 2,000 years ago.

The ruins are on Deling Mountain in western Inner Mongolia, 1.3 km northwest of a section of the Great Wall constructed in the Eastern Han Dynasty (25 AD to 220 AD).

Archeologists believe that the city was built by the rulers of the dynasty to house captured troops of the South Xiongnu, an ancient ethnic group.

The city, covering about 210 hectares, has a rampart 5,850 meters long and a moat outside the city walls.

Inside the city, more than a hundred residences were found in an orderly layout with the characteristics of military camps used by northern ethnic groups in ancient China. A large tent, 32 meters in diameter, was also discovered.

Some pottery unearthed is decorated with wave and bow string patterns and has small holes near the bottom, both signs of the Xiongnu culture.

The Xiongnu people were an alliance of nomadic tribes, also known as the Huns, that emerged around the end of the third century BC and had a huge impact on Chinese and world history. During the Han Dynasty, the Xiongnu and China clashed several times.