Concord is the largest city in Contra Costa County, California, in the United States. At the 2010 census, the city had a population of 122,067. Founded in 1869 as the community of Todos Santos by Salvio Pacheco, the name was changed to Concord within months. Wikipedia

Zhōngshān, previously known as Xiāngshān, is a prefecture-level city in the south of the Pearl River Delta in Guangdong province, People's Republic of China. Zhongshan, one of the few cities in China with an eponymous name, is named after Dr. Sun Yat-sen who is known in Chinese as Sun Zhongshan. Wikipedia