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.
Dingxi is a prefecture-level city under the jurisdiction of Gansu Province, located in central Gansu, commonly known as "Longzhong"; it is located in the confluence area of the Loess Plateau and West Qinling Mountains, with large ups and downs, vertical and horizontal mountains and different shapes; its climate type belongs to the south temperate zone semi-humid-mid-temperate zone semi-arid zone, the continental monsoon climate is obvious; the city's total area is 20330 square kilometers, under the jurisdiction of 1 district, 6 counties; 2018 resident population 2.8217 million. Dingxi is a national summer resort observation city, with more than 60 tourist attractions and tourist spots. Weiheyuan, Guiqing Mountain, Shade Mountain, Langdu Wetland grassland and Taohe tourist promenade are all places for summer leisure. Dingxi not only gave birth to Li culture, but also the intersection of prehistoric cultures such as Majiayao, Qijia, Siwa, Xindian and other prehistoric cultures and important calligraphy and painting in the country.