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.
Yunlong County, located in the longitudinal valley of the Lancang River in western Yunnan, is the joint of Dali Bai Autonomous Prefecture, Baoshan City and Nujiang Prefecture. It is connected to Eryuan and Mianyuan County in the east, Yongping County and Baoshan City in the south, Lushui City in the west and Jianchuan and Lanping County in the north. With a total area of 4400.95 square kilometers, the basic topography is high from east to west and low in the middle, gradually decreasing from north to south. It is a mountainous terrain, with Chongshan Mountains, Panshan Mountains and Qingshuilang Mountains arranged in the south-north direction from west to east, accounting for more than 90% of the total area of Yunlong County. On September 25, 2018, he won the honorary title of "2018 e-commerce into rural comprehensive demonstration county" of the Ministry of Commerce.