Austin is the capital city of the U.S. state of Texas and the county seat of Travis County. Located in Central Texas on the eastern edge of the American Southwest, it is the fourth-largest city in Texas and the fifteenth most populous city in the United States. It was the third-fastest-growing large city in the nation from 2000 to 2006. Austin has a population of 786,386 (2009 U.S. Census estimate). The city is the cultural and economic center of the Austin–Round Rock–San Marcos metropolitan area, with a population of over 1.7 million, making it the 35th-largest metropolitan area in the United States.