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.
Yongdeng, known as Lingju and Zhuanglang in ancient times, belongs to Lanzhou City, Gansu Province, located in the central part of Gansu Province, longitude 102 °36'to 103 °45 'east, latitude 36 °12' to 37 °07 'north. It is bordered by Gaolan County and Jingtai County of Gansu Province to the east, Minhe County of Qinghai Province to the west, Honggu District and Xigu District of Lanzhou City to the south, and Tianzhu Tibetan Autonomous County to the north. The longest distance from south to north is 107km, and the widest distance from west to east is 101km, with a total area of 6090 square kilometers. As of 2010, Yongdeng County has jurisdiction over 13 towns and 5 townships. In 2010, the total population at the end of the year was 522000, and the resident population at the end of the year was 419400. In 2018, the county achieved a gross domestic product (GDP) of 10.831 billion yuan. On January 25, 2019, Yongdeng County was selected as 201.