Riverside County is one of 58 counties in the U.S. state of California. The name was taken from the city of Riverside, which is the county seat. Roughly rectangle-shaped, Riverside County covers 7,208 square miles (18,670 km2) in Southern California. Riverside County lies inland of Los Angeles County and is bordered on the west by Orange County; on the east by La Paz County, Arizona; on the southwest by San Diego County; on the southeast by Imperial County; and on the north by San Bernardino County. Together, Riverside and San Bernardino Counties have been dubbed the Inland Empire.