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.
Zhongning County belongs to Zhongwei City, Ningxia Hui Autonomous region. It is located in the middle of Ningxia and the southern end of Ningxia Plain, between 105 degrees 26 minutes east longitude-106 degrees 7 minutes and 37 degrees 9 minutes-37 degrees 50 minutes north latitude. Located on both sides of the Yellow River, it is the transitional zone between the Inner Mongolia Plateau and the Loess Plateau, belonging to the continental monsoon climate zone of the north temperate zone. Litong District and Qingtongxia City in the east, Zhongwei City in the west, Tongxin County in the south, and Alashan left Banner in Inner Mongolia in the north. The county is about 50 kilometers wide from east to west and 60 kilometers from north to south, with a total area of 4226.5 square kilometers and a total population of 336100 (2013). The government is stationed in Ning'an Town. Zhongning County is located in the confluence of two tourist routes from Yinchuan to Liupanshan and from Yinchuan to Shapotou. It is a "dry wharf" running through the northwest and the collection and distribution of the flow of people, logistics and information.