El Centro is a city in and county seat of
Imperial County, the largest city in the
Imperial Valley, east anchor of the Southern California
Border Region, and the core urban area and principal city of the
El Centro metropolitan area which encompasses all of Imperial County. El Centro is also the largest American city to lie entirely below sea level (-39 feet). The city, located in the far southeastern corner of California, is near the major Southern California city of
San Diego and the
Mexican city of
Mexicali.