The Airplane Programs manufacturing site in Renton, Wash., has been home to many of commercial aviation's most renowned airplanes, including the 707, 727, 737 and 757. Today, employees at the 278-acre site, which encompasses 4.3 million square feet (380,902 square meters) of building space, produce Next-Generation 737 airplanes. The area where 757 wings once were built is now a third 737 final assembly line, opened in March 2008, to produce the P-8 Poseidon.