Kansas City Plant, Missouri

For years this was a diversified weapons and component manufacturing facility, south of Kansas City. Opened in 1942 as an aircraft engine plant operated by Pratt and Whitney, it was later retooled to make non-nuclear components of nuclear weapons, owned by the Department of Energy, and operated by Honeywell. Later known as the Bannister Federal Complex, it was operated by the National Nuclear Security Administration, which in 2014 built a new facility, 8 miles south. The Bannister site, with 300 acres and 4 million square feet of interior space, mostly in one massive building, was declared surplus, with plans to redevelop the area into a commercial industrial center.