World History: Ruins of ancient cities discovered in China

Chinese archeologists have unearthed the ruins of two ancient cities in the central China province of Henan. The cities date back 4,000 years, Ma Xiaolin, deputy director of Henan's provincial cultural heritage bureau, said Thursday.

The discovery will shed light on the development and construction of early cities, culture shifts and the origin of the nation.

One of the cities is believed to be the capital of a tribal state of the Xia Dynasty (2100 BC-1600 BC). The other is thought to be a key military town of the early Shang Dynasty (1,600 BC-1,100 BC).

The two square-shaped cities are located in the Wangjinglou relics site in Xinzheng City. They cover an area of 1.68 million square meters. The military town has a 2,000-square-meter gate, China's oldest discovered defense enclosure. The relics also include city walls, moats, rivers, roads and tombs.