Columbus is one of Georgia's three Fall Line Cities, along with Augusta and Macon. The fall line is where the hilly lands of the Piedmont plateau meet the flat terrain of the coastal plain. As such, Columbus has a varied landscape of rolling hills on the north side and flat plains on the south. The fall line causes rivers in the area to decline rapidly towards sea level, making it a good location for textile mills in the past. The Chattahoochee is the major river that runs through Columbus.