Xi'an is the capital Shaanxi Province One of the oldest cities in China, with more than 3,100 years of history. Xi'an is one of the Four Great Ancient Capitals of China, having held the position under several of the most important dynasties in Chinese history. The city has many important historical sites, and some are ongoing archaeological projects, such as the Mausoleum of Qin Shi Huang and his Terracotta Army. It's now one of the most populous metropolitan areas in inland China with more than 8 million inhabitants. In November 2006, Xi'an and the China Aerospace Science and Technology Corporation jointly set up Xi'an Aerospace Science and Technology Industrial Base. From its establishment, the base has focused on the development of the civil space industry, including equipment manufacturing.