Columbus is a city in the U.S. state of Georgia and the county seat of the consolidated Muscogee County. Columbus is the second largest city in Georgia, it also has the fourth largest metropolitan area of Georgia. According to the 2013 estimates from the U.S. Census Bureau, Columbus has a population of 202,824 residents, with 316,554 in the greater Columbus-Phenix City metropolitan area. The metro area joins the nearby Alabama cities of Auburn and Opelika to form the Columbus-Auburn-Opelika Combined Statistical Area, which has an estimated population of 501,649. Situated at the heart of the Chattahoochee Valley, Columbus is directly to the east across the Chattahoochee River from Phenix City, Alabama.Columbus lies 100 miles southwest of Atlanta. Fort Benning, the United States Army's Maneuver Center of Excellence and a major employer, is located south of the city in Chattahoochee County.