An aircraft graveyard or aircraft boneyard is a storage area for aircraft which are retired from service. Most aircraft at boneyards are either kept for storage continuing to receive some maintenance or parts of the aircraft are removed for reuse or resale and the aircraft are scrapped. Boneyard facilities are generally located in deserts such as those in the southwestern United States, since the dry conditions reduce corrosion and the hard ground does not need to be paved. In some cases, aircraft which were planned to be scrapped or were stored indefinitely without plans of ever returning to service were brought back into service, as the aviation market or the demands of military aviation changed or failed to develop as was anticipated.