Hangar 21 comprises a former domed hangar facility. Vehicle access is gained via full height metal sliding doors in both the front and rear elevations. Aston Down is situated off the A419 equidistant from Cirencester and Stroud, with Swindon approximately 15 miles to the east. The A419 connects the site to Junction 13 of the M5 Motorway to the west 7 ½ miles and Junction 15 of the M4 to the east 20 miles.