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.
Raohe County, which belongs to Shuangyashan City, Heilongjiang Province, is located in the northeast border of Heilongjiang Province, the middle and lower reaches of the Wusuli River, across the river from Russia, the border is 128 kilometers long. The geographical coordinates are 46 °30 °44 "~ 47 °34 °26" N and 133 °07 "26" ~ 134 °20 "16" E respectively. The south is surrounded by the Wanda Mountains and the north is supported by the Sanjiang Plain. The county covers an area of 6765 square kilometers. In 2017, Raohe County has a population of 150000 and has jurisdiction over 4 towns and 5 townships, including 5 state-owned farms and 11 forest industrial forest farms. There are 27 ethnic groups in the county, including 1 Hezhe Township and 3 Korean villages. The county government is stationed in Raohe Town. In the first year of Xuantong of the Qing Dynasty (1909), Shixian County was founded, in 1949 (1925).