Answer: The Wing Plant
Boeing Building Business is alive and well in Everett. This Spring time photo shows the airplane will be built. The wing will roll out on a specialized carrier frame rolling into the 777 manufacturing site straight into the production building.
Note the orange or yellow colors of cranes in the background (center back of roof line). This is the wing plant under construction just behind the World's largest building. The Wing center remains dwarfed by the main show in the front of this photo.
It will receive the title of World's Largest Twin Engine Passenger Jet. It will be built in the World's Largest Building next to the Word's Largest Wing Manufacturing Facility. Records are made, to be broken. Today is Boeing's day as it embarks on a fanciful journey of airplane building, because it can. There is no glory in accomplishing what it can do anyways, as Airbus would have you believe. There is only glory in doing what no one else can do. Build planes that are needed for the existing market.