Enclosure for aircraft. Often used for maintenance and reapir too. If armoured called shelter.
Ideal background for model photos. If you have no suitable poster available (remember the next airshow), it can be easily built. Normally the front part is sufficient. I made mine from a piece of styrofoam with a layer of cardboard where various pieces of polystyrene were glued onto and painted light gray. The "sky" background is light blue cardboard. See page "Modellfotos 3"
Even better, of course, is to show the hangar from the inside with an aircraft parked. For the outer walls you take a box (of course, leave at least one wall free), T-beams, fire extinguishers, etc. can be found in the accessory trade. I