San Diego (/ˌsæn diˈeɪɡoʊ/ SAN dee-AY-goh, Spanish: [san ˈdjeɣo]; Spanish for 'Saint Didacus') is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States and the seat of San Diego County, the fifth most populous county in the United States, with 3,338,330 estimated residents as of 2019. The city is known for its mild year-round climate, natural deep-water harbor, extensive beaches and parks, long association with the United States Navy, and recent emergence as a healthcare and biotechnology development center. San Diego is the second largest city in the state of California, after Los Angeles.
Nanjing (ancient Zhangzhou capital, Nanjing County) was called Lanshui County in ancient times. It bought the county in the second year of Yuan Dynasty (1322). Located in the northwest of Zhangzhou City, with an area of 1962 square kilometers and a population of 360000, it has jurisdiction over 11 towns and 1 state-level high-tech industrial park, including 183administrative villages and 18 community neighborhood committees. Nanjing is one of the key hometown of overseas Chinese and one of the important ancestral places of Taiwan compatriots in Zhangzhou, with more than 30,000 overseas Chinese and more than 1 million Taiwan compatriots from Nanjing. Vincent Siew, Annette Lu and other Taiwan celebrities are all in Nanjing. "Top Ten" counties (cities) for county economic development in Fujian Province in 2019.