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.
Wenchang, known as Zibei in ancient times, has a history of more than 2100 years since the Western Han Dynasty. It is one of the three historical ancient cities in Hainan. It is a famous hometown of overseas Chinese in China and one of the important base areas of the Qiongya Revolution. The birthplace of Minnan culture in Hainan, the location of Hainan Wenchang Space launch Center, is the fourth space city in China. It is located in the integrated economic circle of "one hour Economic Circle" and "Haicheng text" in Qiongbei Comprehensive Economic Zone. Qiongbei is one of the important regional centers of economy, culture, transportation, science and technology and tourism. Wenchang, Haikou and Sanya have been selected as "charming cities with Chinese characteristics" by global organizations. they are national demonstration cities for scientific and technological progress, national advanced cities for scientific and technological progress, and advanced cities for national culture. The city with 278.5 kilometers of coastline is the longest in Hainan, and Qinglan Port in the city is open to the outside world at the national level.