Southern California (SoCal) is the southern area of the U.S. state of California. Though there is no official definition for the northern boundary of Southern California, most definitions in use include all the land south of the Tehachapi Mountains, located about convert70mikm0sp=us north of Los Angeles. Southern California can be divided into Greater Los Angeles (Greater Los Angeles Area), the Inland Empire (Inland Empire (California)), and the Border Region (San Diego-Imperial, California). Southern California is a large cultural and economic center for the State of California.Citation neededdate=March 2010

Its population encompasses a total of five metropolitan areas: Los Angeles (Los Angeles metropolitan area), Riverside-San Bernardino (Inland Empire (California)), San Diego (San Diego metropolitan area), Oxnard-Thousand Oaks (Oxnard-Thousand Oaks-Ventura metropolitan area) and the El Centro (Imperial County, California) area. Out of these, three are major metropolitan areas, each of which have over 3 million people; the Los Angeles area with over 12 million inhabitants, the Riverside-San Bernardino area with over 4 million inhabitants, and the San Diego area with over 3 million inhabitants. The region as a whole is home to approximately 24 million people, which is more than half of Californias population, and is the nations most populous region behind the urban seaboard of the Northeastern United States.

To the west of Southern California lies the Pacific Ocean; to the south is the international border (Mexico - United States border) between the United States and Mexico; to the east are the Mojave (Mojave Desert) and Colorado (Colorado Desert) Deserts and the Colorado River at the states border with Arizona and Nevada.