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.
Lintao County, known as Didao in ancient times, belongs to Dingxi City, Gansu Province, and gets its name because of the Tao River in the territory. Lintao County is located in the middle of Gansu Province and the west of Dingxi City. It is located in the confluence zone of the Loess Plateau and the Qinghai-Tibet Plateau. Tao River, the largest tributary in the upper reaches of the Yellow River, passes through the city. As of October 2018, the county has a total area of 2851 square kilometers and a total population of 552900. There are 21 ethnic groups, including Han, Hui and Dongxiang, under the jurisdiction of 12 towns and 6 townships, with the county government stationed in Taoyang Town. Lintao has been a famous city in the northwest and an important town in Longyou since ancient times. it is located on the main road of the ancient Silk Road and is one of the important birthplaces of the ancient culture of the Yellow River. Since the establishment of Didao County in the 18th year of King Zhou'an (384 BC) and the establishment of Longxi County in the 27th year of King Zhao of Qin Dynasty (280 BC), it has been a county, state, state, government and county government.