San Diego ("Saint Didacus") is a major city in California, on the coast of the Pacific Ocean in Southern California, approximately (190 km) south of Los Angeles and immediately adjacent to the border with Mexico.
With an estimated population of 1,381,069 as of July 1, 2014,San Diego is the eighth-largest city in the United States and second-largest in California.
It is part of the San Diego-Tijuana conurbation, the second-largest transborder agglomeration between the US and a bordering country after DetroitÃ¢ÂÂWindsor, with a population of 4,922,723 people.
San Diego is the birthplace of California and is known for its mild year-round climate, natural deep-water harbor, extensive beaches, long association with the United States Navy and recent emergence as a healthcare and biotechnology development center.
San Diego was the first site visited by Europeans on what is now the West Coast of the United States. Upon landing in San Diego Bay in 1542, Juan RodrÃÂguez Cabrillo claimed the entire area for Spain, forming the basis for the settlement of Alta California 200 years later.
The Presidio and Mission San Diego de AlcalA, founded in 1769, formed the first European settlement in what is now California. In 1821, San Diego became part of the newly-independent Mexico, which reformed as the First Mexican Republic two years later.
In 1850, it became part of the United States following the Mexican-American War and the admission of California to the union.
The presence of the University of California, San Diego (UCSD), with the affiliated UCSD Medical Center, has helped make the area a center of research in biotechnology.