A visitor takes a photo of an exhibit at a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province, July 16, 2013. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)

Combination photo taken on July 16, 2013 shows exhibits at a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)

Combination photo taken on July 16, 2013 shows a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)

A visitor views an exhibit at a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province, July 16, 2013. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)

A visitor takes a photo of an exhibit at a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province, July 16, 2013. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)

A visitor takes a photo of an exhibit at a public exhibition presenting elaborate antiques of the Xixia Kingdom at the Heilongjiang Provincial Museum in Harbin, capital of northeast China's Heilongjiang Province, July 16, 2013. Xixia (1032-1227), or Western Xia, was a feudal kingdom established by the Tangut ethnic group at the eastern end of the ancient Silk Road. Its territory largely overlapped today's Ningxia Hui Autonomous Region in northwest China. (Xinhua/Wang Song)