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.
Longzi County, which belongs to Shannan City, Tibet Autonomous region, is located in the south of Shannan City, in the eastern part of the northern foot of the Himalayas, bordering Lang County and Jiacha County in the north, Menjiu County in the south, Luoyu County in the east and Cuomei County in the west, Cuona County in the southwest, Qusong County in the north, Nedong District in Shannan City in the northwest, and Milin County in the northeast. Its geographical location is 91 °53km east longitude, 93 °06km east longitude and 28 °07mm north latitude, with a total area of 10566 square kilometers and an actual control area of 8165 square kilometers. As of 2018, Longzi County has jurisdiction over 2 towns and 9 townships. By the end of 2017, the total population of Longzi County was 35858, with a regional gross domestic product (GDP) of 1.099 billion yuan, of which the added value of the primary industry was 64.185 million yuan and the second production was the second.