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.
Daiyue District, located in Taian City, Shandong Province, is located in the hinterland of Qilu, Jinan, the provincial capital, Qufu, the hometown of Confucius, between latitude 35 °52 "29"-36 °28 "36" and longitude 116 °50 "26"-117 °28 "16" east. It is 66 kilometers from north to south and 56 kilometers from east to west, with a total area of 917.2 square kilometers. The overall topography of Daiyue District is high in the north and low in the south, high in the east and low in the west, with mountains, hills and plains accounting for 1/3 each, which belongs to the temperate continental semi-humid monsoon climate. It is the birthplace of the ancient civilization "Dawenkou culture". In the Spring and Autumn and warring States period, it has the reputation of "plucking the land since ancient civilization, Qilu must compete for Wenyang field". During the Western Han Dynasty, Liu an, king of Huainan, left here the chant of "the beauty of the central government, there is Daiyue".