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.
Yuncheng District, which belongs to Yunfu City, is located in the central and western part of Guangdong Province, on the south bank of the middle reaches of the Xijiang River, high in the southwest and low in the northeast, bordering Zhaoqing in the east, Yunan District in the west, Xinxing County in the south and Xijiang in the north. Jurisdiction over 4 streets and 4 towns. By the end of 2018, the total population of the region will be 350000, including more than 55000 compatriots from Hong Kong, Macao and Taiwan and overseas Chinese living overseas. The 324 National Highway and the Yunyao branch of Sanmao Railway crisscross. Yuncheng District has a superior geographical environment and belongs to the subtropical monsoon area with mild climate and abundant rainfall. The region is rich in mineral resources, known as "sulfur capital" and "hometown of dolomite". There are more than 50 kinds of proven mineral deposits, among which pyrite reserves and grade rank first in the world, and marble, granite and limestone reserves are also very large. Panlong Cave in the city is a provincial scenic spot.