Researchers from the Shaanxi Academy of Archaeology work at the Xianyang site, Shaanxi province, in December. ZHANG JIE/FOR CHINA DAILY

Xu Weihong checks a vase. ZHANG XIPING/FOR CHINA DAILY

Tiles from the ancient city have been found at the ruins in Xianyang. ZHANG JIE/CHINA DAILY

Zhang Yanglizheng and Xu Weihong, a researcher from the academy and leader of the team, study relics found at the Xianyang site. ZHANG XIPING/FOR CHINA DAILY

Zhang Yanglizheng, from the Shaanxi Academy of Archaeology, right, and a worker from the local relics bureau examine a tile found in the ruins. ZHANG XIPING/FOR CHINA DAILY