The National Museum of the United States Air Force, located at Wright-Patterson AFB, Dayton, Ohio. Dating from 1923, the current museum displays over 350 aircraft in four large buildings. Walking tours of each building, led by knowledgeable volunteers, provide an overview of the collection in about 90 minutes. The collection includes large aircraft (B-36, B-52, XB-70), as well as details such as flying jackets, uniforms, and flight suits. Many of the artifacts are unique, one of a kind items, e.g., the XB-70, the Shuttle trainer, and four Presidential aircraft.