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.
Longchang is a county-level city hosted by Neijiang City in Sichuan Province, which is located in the southeast of Sichuan Province and the southern end of Neijiang City. The ground span ranges from 105 degrees 02 to 105 degrees 26 degrees east longitude and from 29 degrees 11 to 29 degrees 32 degrees north latitude. It is adjacent to Rongchang District of Chongqing City in the east, Lu County of Luzhou City in the south, Fushun County of Zigong City and Daan District of Zigong City in the west, Dongxing District in the north, 210 kilometers away from Chengdu and 138 kilometers away from Chongqing. Longchang covers an area of 794.41 square kilometers; it has jurisdiction over 2 streets and 13 towns; it has a total population of 778000 in 2015; in 2015, Longchang achieved a GDP of 23.3 billion yuan and a per capita GDP of 36096 yuan. Belongs to the subtropical humid monsoon climate, the annual average temperature is 17.7 ℃, the frost-free period is 324 days, and the annual rainfall is 10%.