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.
Yanyuan County, which belongs to Liangshan Yi Autonomous Prefecture of Sichuan Province, is located on the southeast edge of the Qinghai-Tibet Plateau in Sichuan Province and on the west bank of the lower reaches of the Yalong River. The geographical coordinates are: longitude 100 °42 °09 "- 102 °03 °44" east and latitude 27 °06 °31-28 °16 °31 "north. Across the Yalong River from Xichang City, Dechang County and Miyi City in the east, Yanbian County in the south, Ningyi County in Yunnan Province in the west, and Muli Tibetan Autonomous County and Mianning County in the north. As of 2012, Yanyuan County covers an area of 8398.6 square kilometers and has a population of 356000. Yanyuan County, which belongs to Sichuan Province, contains 41 kinds of mineral resources, such as salt, iron, gold, etc.; it is rich in many kinds of rare animals, such as black-crowned crane, bear, Swertia, etc., and is rich in apple, Phnom Penh melon seeds and other famous and special products, which is the apple production in southwest China.