Located a few miles southeast of Seattle, the Renton manufacturing facility once was a marsh through which the Cedar River flowed. Throughout the years, 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 4.1 million square feet (380,902 square meters) of building space, produce the Boeing Next-Generation 737 airplane models.