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.
Danzhou City is a prefecture-level city in Hainan Province. Danzhou City is located in the northwest of Hainan, bordering on the Beibu Gulf, 130km north to Haikou, the provincial capital, and 280km south to Sanya City; it has jurisdiction over 16 towns, a total of 275village committees and 1431 natural villages; the land area is 3400 square kilometers, accounting for 1x10 of the province; the total registered population is 945400 (2016); and the coastline is 267km long. Danzhou City is the economic, transportation, communication and cultural center of western Hainan. Hainan Yangpu Economic Development Zone, Chinese Academy of Tropical Agricultural Sciences and Danzhou Campus of Hainan University (formerly South China Tropical Agricultural University) are all in its territory. Danzhou City has successively won the "National Agricultural Top 100 City", "National Sanitary City", "National Civilization demonstration City", "National Garden City" and "National Garden City".