The huge 30' main fan and duct of the Q121 wind tunnel at the historic Royal Aircraft Establishment in Farnborough, UK. Built to test the entire airframe of small biplanes at the end of the 1st World War. Later the tunnel was used for a variety of purposes including testing the aerodynamic properties of other vehicles such as boats and cars. The building has not been in use for a long time and currently sits in a disused state, locked away from public view. This building and other wind tunnels located nearby played a huge role in the early development of aircraft development.
The interior of the building is incredibly well preserved considering its age and is exactly how it would have been back in the 1930's.