The Varsity Line, which was first opened in 1846, will be the focus of Channel 4’s Abandoned Railways From Above, which is set to air on Saturday, September 28.

The railway line was a vital link between the two university cities, and its route crossed seven main lines and passed through Bedford, Bletchley, and Bicester on its way to Oxford.

Roland Gillott outside Rewley Road Station (Image: STV) The programme will reveal how the line came into its own during World War Two and became Britain’s secret weapon by helping to feed the nation and even facilitating the cracking of Nazi war codes.

Thomas Cheetham, research officer at the Bletchley Park Trust, said: “It was certainly a benefit for staff coming from Oxford and Cambridge that they could get the train easily to Bletchley on the Varsity Line.

“Most people arriving at Bletchley came on the train – most people didn’t have cars.

The route finishes at Rewley Road Station (Image: STV) “When they arrived, they were either given directions up to Bletchley Park or they were instructed to ring a particular phone number and they were picked up and driven round the corner.

“But we don’t know of any secret signals that were given and we also don’t know of any secret tunnels from the station up to Bletchley Park.”

The programme will also explore the line’s role as an “information super highway” during the country’s most challenging period.

Abandoned for decades, some of the line’s winding route is now slowly coming back to life as part of the East West Rail strategy to establish a new main line railway between East Anglia and South Wales.

The programme begins at Cambridge Station before passing through the Cambridgeshire countryside, where the line has returned to nature since its closure more than half a century ago.

The part of the line which passes through the Cambridgeshire countryside has been taken over by nature (Image: STV) The route mapped out in Abandoned Railways From Above concludes at the disused Rewley Road Station, which once served Oxford but is now no longer in the city.

Abandoned Railways From Above is a six-part series, with each episode exploring a different lost railway line with its own history, revealing the industries that were once dotted along its route, and examining the engineering that was needed to build it.

This weekend’s episode, which will be shown at 8pm and be available on Channel 4’s streaming service, will also highlight how the line transformed the lives of people in the cities, towns, and villages that it once passed through.