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.
Longmatan District, which belongs to Luzhou City, Sichuan Province, is located in the south of Sichuan Basin, at the confluence of the Yangtze River and Tuojiang River. It intersects with Lu County in the west and north, Jiangyang District in the south and Lu County and Jiangyang District in the east. Longmatan District is the trade, logistics, economic and passenger transport center of Luzhou. It is a developed economic and trade area of Luzhou and one of the three main cities of Luzhou. At the same time, the Lingang area in southern Sichuan, a free trade pilot zone in China (Sichuan), is located in Longmatan District. Longmatan District covers an area of 332.64 square kilometers and has jurisdiction over 7 streets and 5 towns. In 2013, Longmatan District had a total registered population of 357000 and a resident population of more than 500,000. GDP reached 16.188 billion yuan, an increase of 13.1% over 2012 at comparable prices. On February 2, 2019, it was rated as the national base at the county level by the State Administration of traditional Chinese Medicine.