San Antonio ( Spanish for “Saint Anthony”), officially the City of San Antonio, is the seventh most populous city in the United States of America and the second most populous city in the state of Texas, with a population of 1,409,019. It was the fastest growing of the top 10 largest cities in the United States from 2000 to 2010, and the second from 1990 to 2000. The city is located in the American Southwest, the south–central part of Texas, and the southwestern corner of an urban region known as the Texas Triangle. San Antonio serves as the seat of Bexar County. The city has characteristics of other western urban centers in which there are sparsely populated areas and a low density rate outside of the city limits. San Antonio is the center of the San Antonio–New Braunfels Metropolitan Statistical Area. Commonly referred to as Greater San Antonio, the metropolitan area has a population of over 2.27 million based on the 2013 US Census estimate, making it the 25th-largest metropolitan area in the United States and third-largest in the state of Texas. Growth along the Interstate 35 and Interstate 10 corridors to the north, west and east make it likely that the metropolitan area will continue to expand. San Antonio was named for Saint Anthony of Padua, whose feast day is on June 13, by a 1691 Spanish expedition in the area. It is notable for Spanish colonial missions, the Alamo, the River Walk, the Tower of the Americas, the Alamo Bowl, and Marriage Island. Commercial entertainment includes SeaWorld and Six Flags Fiesta Texas theme parks, and the city is visited by approximately 26 million tourists per year, according to the San Antonio Convention and Visitors Bureau. The city is home to the five-time NBA champion San Antonio Spurs and hosts the annual San Antonio Stock Show & Rodeo, one of the largest such events in the country. The US armed forces have numerous facilities in San Antonio: Fort Sam Houston, Lackland Air Force Base, Randolph Air Force Base (which constitute Joint Base San Antonio), and Lackland AFB/Kelly Field Annex, with Camp Bullis and Camp Stanley located outside the city. Kelly Air Force Base operated out of San Antonio until 2001, when the airfield was transferred to Lackland AFB. The remaining portions of the base were developed as Port San Antonio, an industrial/business park. San Antonio is home to six Fortune 500 companies and the South Texas Medical Center, the only medical research and care provider in the South Texas region.