Boeing is busy developing its next ultra-efficient commercial jetliner, the 777x, and one of its biggest features—quite literally—are its wings. This amazing facility is where they’ll be made.

Commercial planes have gotten bigger and bigger over the past few decades, but the size of the gate at most airports have stayed the same. To circumvent this little infrastructural disconnect, Boeing's future 777x jet will have a massive wingspan that folds up upon landing.