San Diego County, California

San Diego County, officially the County of San Diego, is a county in the southwestern corner of the state of California, in the United States. As of the 2010 census, the population was 3,095,313,[5] making it California’s second-most populous county and the fifth-most populous in the United States. Its county seat is San Diego,[8] the second-most populous city in California and the eighth-most populous city in the United States. It is the southwesternmost county in the 48 contiguous United States, and is a border county.

San Diego County comprises the San Diego-Chula Vista-Carlsbad, CA Metropolitan Statistical Area,[9] which is the 17th most populous metropolitan statistical area and the 18th most populous primary statistical area of the United States as of July 1, 2012.[10][11] San Diego County is also part of the San Diego–Tijuana transborder metropolitan area, the largest metropolitan area shared between the United States and Mexico.