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.
Daye, a county-level city under the jurisdiction of Hubei Province, administered by Huangshi City, is located in the southeast of Hubei Province, the south bank of the middle and lower reaches of the Yangtze River, the hinterland of Hubei "Metallurgical Corridor", an important part of Wuhan city circle, with a total area of 1566.3 square kilometers. Daye is the birthplace of Chinese bronze culture. More than 3000 years ago, Chinese ancestors mined and smelted copper in Daye, creating a bronze civilization. The Tonglushan ancient copper mine site in the territory is known as "the ninth wonder of the world". It has been listed in the National Archaeological site Park project and the preliminary list of "World Cultural Heritage", and has been awarded the Guinness record of "Ancient Copper Mine with the longest continuous Mining time". Tonglushan Sifangtang site was selected as one of the Top Ten Archaeological discoveries in China in 2015. As of