Southern California, or SoCal, is defined as the southern portion of the U.S. state of California. Its population centers around three major metropolitan areas, each of which have over 3 million people; the Los Angeles Metropolitan Area with over 12 million inhabitants, the San Bernardino-Riverside Metropolitan Area with over 4 million inhabitants, and the San Diego Metropolitan Area with over 3 million inhabitants. The region is home to approximately 24 million people and is the nation's second most populated region, behind only the BosWash Region in the Northeastern United States.
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 70 miles (113 km) north of Los Angeles.
On the west of Southern California lies the Pacific Ocean; to the south is the international border between the United States and Mexico; to the east are the Mojave and Colorado Deserts and the Colorado River at the state's border with Arizona and Nevada.
