Austin is the capital of the U.S. state of Texas and the county seat of Travis County. Situated in Central Texas and part of the American Southwest, it is the fourth-largest city in Texas and the 16th-largest in the United States of America. It was the third-fastest-growing large city in the nation from 2000 to 2006. According to the 2007 U.S. Census estimate, Austin had a population of 743,074. The city is the cultural and economic center of the Austin–Round Rock Metropolitan Area, with a population of 1,652,602 as of the July 2008 U.S. Census estimate—making it the 36th-largest- and 2nd-fastest-growing metropolitan area in the nation.