The base of this picket post is at the Southern entrance to the airfield on the Western side of Roborough Rock. The picket post or guard house was the place where any official visitors were checked in to and out of the airfield. Airmen had to check in and out of the picket post as they entered and left the airfield. The orderly officer would also issue keys, check the dress and discipline of airmen, investigate minor crime and deal with lost property. Behind the picket post is the iron base of an Allan Williams Turret, part of the airfield defences. Photograph taken July 2001.