Chinese archaeologists have excavated 4,000-year-old fortifications of the largest neolithic-era city ever discovered, in northwestern Shaanxi Province.
The ruins of two square beacon towers, once part of the city wall of the Shimao Ruins in Shenmu County, have been uncovered in the last two days, Shaanxi Provincial Institute of Archaeology said.
One of the towers is 18 metres long, 16 metres wide and four metres tall, while the other is 11.7 metres long, about 10 metres wide and three metres tall, Sun Zhouyong, deputy head of the institute told state-run Xinhua news agency.
Sun said the discovery is a breakthrough and contributes greatly to archaeological research on ancient Chinese fortifications.
The Shimao Ruins were first found in 1976 in the form of a small town, and archaeological authorities only identified the ruins as part of a much larger city -- the largest of its kind from neolithic times -- last year after measuring the exact size of the ancient stone city.
The city was found to have a central area, and inner and outer structures.
The walls surrounding the outer city extended over an area of 4.25 square kilometers.
Archaeologists said it was built about 4,300 years ago and was abandoned roughly 300 years later during the Xia Dynasty, the first dynasty in China to be described in ancient historical chronicles.
