Hartsfield–Jackson Atlanta International Airport now the airport's second largest carrier. In May 2001 construction of an over fifth runway (10–28) began. It was completed at a cost of $1.28 billion and opened on May 27, 2006. It bridges Interstate 285 (the Perimeter) on the airport's south side, making Hartsfield–Jackson the nation's only civil airport to have a runway above an interstate (although Runway 17R/35L at Stapleton International Airport in Denver, Colorado crossed Interstate 70 until that airport closed in 1995). The massive project, which involved putting fill dirt eleven stories high in some places, destroyed some surrounding neighborhoods and dramatically changed the scenery of
Stapleton International Airport tower has been retained as part of the new Punch Bowl Social, a restaurant and social gathering spot. The office building attached to the tower houses the kitchens and social areas; the tower is closed to public access but is available for private tours. All of Stapleton's airport infrastructure has been removed, except for the former control tower. The final parking structure was torn down to make room for the "Central Park West" section of the housing development in May 2011. D.I.A. still owns some land at the former Stapleton site, an open field area bordered by Central Park Blvd