4076 - Tucson, Arizona, United States

Eight kilometres from downtown Tucson is Davis-Monthan Air Force Base. It was established in 1925. It is home of the 355th Wing assigned to the Twelfth Air Force, part of Air Combat Command. However, the base is better known as the location of Air Force Materiel Command's 309th Aerospace Maintenance and Regeneration Group, which is an aircraft boneyard for all excess military and US government aircraft and aerospace vehicles. 

The 309th takes care of nearly 4000 aircraft, which makes it the largest aircraft storage and preservation facility in the world. The arid climate prevents the aircraft from corroding. The ground is so hard that they do not sink in the ground. 

There are four categories of storage for aircraft at the 309th:

• Long Term - aircraft are kept intact in inviolate storage for future use. No parts are removed without the express permission of appropriate program office.
• Parts Reclamation - aircraft are kept, picked apart, and used for spare parts.
• Flying Hold - aircraft are kept intact with regular running of their engines, towing to lubricate their bearings and servicing fluids.
• Excess of DoD needs - aircraft are sold off whole or in parts.