Arlington is a city in the U.S. state of  Texas , within the  Dallas–Fort Worth–Arlington  metropolitan area and  Tarrant County . According to the U.S. Census Bureau’s estimate, the city had a population of almost 374,000 at the end of 2011, [3]  making it the third largest municipality in the metropolitan area. Arlington is the  fiftieth most populous  city in the United States, the seventh most populous  city in the state of Texas, [4]  and the largest city in the state that is not a county seat. Arlington is the largest city in the United States without a comprehensive public transit system. [5]

Located approximately 12 miles (19 km) east of  downtown Fort Worth  and 20 miles (32 km) west of  downtown Dallas , Arlington is home to the  University of Texas at Arlington , a doctoral-granting institution, and a General Motors assembly plant. Additionally Arlington hosts the  Texas Rangers’ Rangers Ballpark in Arlington ,  AT&T Stadium , the International Bowling Campus (which houses the  United States Bowling Congress ,  International Bowling Museum  and the  International Bowling Hall of Fame ), the headquarters for  American Mensa , and the  theme parks  Six Flags Over Texas  (the original Six Flags) and  Hurricane Harbor . Arlington is the headquarters of the  Nuclear Regulatory Commission Region IV .

Arlington borders  Kennedale ,  Grand Prairie ,  Mansfield  and  Fort Worth , and surrounds the smaller communities of  Dalworthington Gardens  and  Pantego .