Chinese archaeologists say the discovery of tombs and ruins of residential structures in northwest China offers a glimpse into nomadic life in the Bronze Age. The settlement in the country\'s Xinjiang Uygur autonomous region dates back 3,700-3,900 years, placing it in the time of the Xia Dynasty (2070-1600 B.C.), the first Chinese dynasty to be described in ancient documents, China\'s state-run Xinhua news agency reported Thursday. In addition to nearly 100 tombs, the center of the stone ruins features a uniquely designed residential structure, leading archaeologist Cong Dexin of the Chinese Academy of Social Sciences said. \"The ruins of the structure are the first of their kind to be found in Xinjiang,\" he said. The settlement is located south of the Qagan Usu pass at Mount Alataw, which borders Kazakhstan. The tombs were built with stones weighing as much as 1 ton, although it isn\'t known how the nomads were able to cut and carry such large stones, Cong said. \"The tombs and ruins of residential structures are contemporaneous,\" he said. \"This is the only archaeological site in Xinjiang where one can see dwellings for the living and the deceased at the same time.\" \"Hopefully, we\'ll find out more about the mysteries of ancient nomads in northwest China.\"