Santa Clara County is located at the southern end of the San Francisco Bay Area and includes all of the City of San Jose, which is the 10th largest city in the United States. As of 2010, the County had a population of 1,781,642. Santa Clara County is also known as the Silicon Valley. Santa Clara is the most populous county in the Bay Area region, and one of the most affluent counties in the United States. It is also known to have one of the best-run local governments.