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.
Lu'an is a prefecture-level city in Anhui Province. Located in the west of Anhui Province, known as "Gaocheng" for short, located between the Yangtze River and the Huaihe River, the northern foot of the Dabie Mountains, the west wing of the Yangtze River Delta economic zone, the geographical meaning of "West Anhui" specifically refers to Liu'an. Liu'an is located in Jianghuai, with Wu Yue in the east, Jingchu in the west and the Central Plains in the north; the terrain is high in the southwest and flat in the northeast, showing a trapezoidal distribution; it belongs to the transition zone from the north subtropical zone to the warm temperate zone, with significant monsoons and four distinct seasons. In 2017, the city has a total area of 15451 square kilometers and a registered population of 5.882 million. It has jurisdiction over 3 districts and 4 counties. The name of Lu'an began with Emperor Wu of the Han Dynasty, taking the first words of six counties in Hengshan, Anfeng and Anfeng, and other Hengshan countries as Lu'an, with the meaning of "peace in six places, never rebellion". Because Shun Feng Gao Tao in six, so later generations called Liu'an