Each of the seven hangars of the Pima Air & Space Museum is devoted to a theme, a period of aviation history or World War II: volunteers are on site to explain the displays and talk about the aircraft. The tarmac is dotted with some 260 planes, including Air Force One, some of which are still in working order. A small train takes visitors around most of the museum and it is also possible to visit the "airplane cemetery" in the neighboring military base.