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.
Longling County is located in the west of Yunnan Province, with geographical coordinates of 98 °25 "99 °11" east longitude and 24 °07 "24 °50 'north latitude. It is bordered by Shidian, Yongde, Zhenkang, Myanmar, Luxi, Lianghe, Tengchong and Longyang respectively. The maximum distance between east and west of the county is 64 kilometers, and the maximum span between north and south is 78 kilometers, with a total area of 2884 square kilometers. The county has jurisdiction over 5 towns and 5 townships (including 1 ethnic township). Longling is located in the Nujiang fault zone, with many earthquakes and geothermal. Belongs to the subtropical mountain monsoon climate, the three-dimensional climate is obvious, the annual precipitation is about 2300 mm, it is called "the rain screen of western Yunnan". Places of interest include Xiao Heishan Nature Reserve, Banglazhang Hot Mineral Spring, Songshan Battle site, Dam Martyrs Cemetery, Xishan Park, Yunlong Temple, etc., as well as Hetou Shaotan Tianpo, etc.