San Jose is the third-largest city in California, the tenth-largest in the United States, and the county seat of Santa Clara County. Anchor to the 31st-largest metropolitan area in the country, it is located at the southern end of San Francisco Bay. Sannn Jose was founded on November 29, 1777, as El Pueblo de San Jos‚ de Guadalupe, the first town in the Spanish colony of Nueva California, which later became Alta California. The large concentration of high-technology engineering, computer, and microprocessor companies around San Jose has led the area to be known as Silicon Valley. As the largest city in the valley, San Jose has billed itself "the capital of Silicon Valley."