A former military airfield, now a civil airport. The airfield was opened in 1941 and used during World War Two. It was then known as Middleton St. George and was equipped with three tarmac runways and a range of aircraft hangars, including types C, J,T2 and B1. In that conflict it was an operational bomber station; the base for a sequence of units including squadrons of the Royal Canadian Air Force. In the 1950s the airfield was rebuilt and runways extended for use by jet aircraft. In 1965 the Royal Air Force station closed and in 1966 the airfield was reopened as a civil airport, and known as Teesside International Airport until 2004, when it was renamed Durham Tees Valley Airport. It was then further extended in 1987. The present airport still uses the wartime control tower (modified in the 1950s) for flying control. A number of other wartime buildings from dispersed sites near the flying field, including airmen's accommodation and the officers' mess are extant and in use for civil non-aviation purposes. Some of the airfield's wartime defences are also extant.