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.
Yilong County, which belongs to Nanchong City, Sichuan Province, is located in the northeast of Nanchong City, Sichuan Province. Nanchong County, 244 National Highway, 245 National Highway, 205 Provincial Highway, 206 Provincial Highway, 207 Provincial Highway, 304 Provincial Highway, Chengba Expressway and Ba-Guang-Yu Expressway run through or transit through Yilong County. Yilong County has undulating mountains, vertical and horizontal gullies, complex terrain, mild climate, four distinct seasons, sufficient heat, abundant rainfall, rain and heat in the same season, with a total area of 1791 square kilometers, including 29 towns, 7 townships and 1 street. Yilong County is an agricultural county based on planting and breeding industry, and it is the first county in the rabbit industry in the country, a key county in modern animal husbandry in the province, a key county in the construction of high-standard grain fields in the province, a demonstration county in agricultural technology popularization and fertilization in the country, and a demonstration county in soil testing and formula fertilization. It is rich in wheat, rape, rice, red potato, citrus and so on.