Yan'an is sacred ground for China's revolutionary history,but also a place that has lagged in economic and cultural development for a long time.In October 1935,the CPC Central Committee arrived at Wuqi Town with the Central Red Army at the end of the Long March.They set up a base in Yan’an proper at the beginning of 1937,where they stayed until March 1948.These 13 years are known as the Yan’an period.