It is what is commonly referred to as an aircraft hangar...push and hold a couple buttons and one of the walls magically splits in half and opens like "really big" sliding doors...if you walk through them, you'll soon find yourself exposed to the elements...aka...rain, wind, snow...etc.. while indoors, we don't stop what we're doing, nor do we stand at attention or salute. Same goes for the flight line...(the place you end up when you walk outside the  "really big" doors