San Diego County
San Diego County is the southwestern-most region of Southern California. It encompasses the city of San Diego and its large metropolitan area, which includes many smaller cities and communities. San Diego County lies along the U.S.-Mexican border, across from the Mexican city of Tijuana.
Besides San Diego, there are many smaller cities in the county. Listed here are the major ones:
San Diego County covers a very large area (4,526 square miles, to be exact) with incredibly varied topography. The western half of the county is mostly urbanized, and includes the city of San Diego and its many suburbs to the south, east, and north. The climate of the western half is more moderate, due to its proximity to the ocean, giving San Diego its signature weather. The eastern half is mostly uninhabited or rural, contains snow-capped mountains, forests, and barren desert, and is prone to more extreme weather.
Like much of California, English and Spanish are the dominant languages in San Diego County. Typically, most businesses have at least a few employees that are bilingual in English and Spanish, and some people will be bilingual in English and Tagalog (mostly by San Diego's large Filipino population). It is also common to see store signs printed in both English and Spanish, especially in neighborhoods with large Hispanic populations.
For detailed information on getting in to San Diego, see the Get in section of San Diego.
There are two commercial airports in San Diego County: San Diego International Airport (IATA: SAN) is by far the major one, served by many airlines offering flights from cities around the country and some international flights to Mexico and Canada. McClellan-Palomar Airport (IATA: CLD) in Carlsbad serves a couple of commuter airlines providing service from Los Angeles and Phoenix.
Amtrak's frequent Pacific Surfliner  San Luis Obisbo-Los Angeles-San Diego route serves San Diego County with four stops: one in Oceanside, one in Solana Beach, one at the southern end of the line at Union Station in Downtown San Diego, and a secondary station in Old Town San Diego which is served on weekends.
Three major interstate roadways, I-5, I-8, and I-15, lead into San Diego County. I-5 runs from the north along the coast, I-8 comes in from the east through the desert, and I-15 leads in to San Diego from the northeast.