It was also one of the first to go, closing in 1966.

This programme looks at the building of the line, and explores the route from Marylebone to Helmdon just to the south of Woodford Halse.

On the way we explore the motive power, engineering structures and stations.

The programme comprises:

Watkins' great plan for the London Extension
The conception and buiilding of the railway, together with its link lines to the Great Western Railway.

Marylebone Station
Its building and operations in the days of working steam together with the return of steam in the 1980s.

Through the London Suburbs
The approach to Marylebone, the terminus itself and the line through Harrow on the Hill to Rickmansworth in the days of steam including steam on Metropolitan services.

Through the Chilterns
Steam on the line through Wendover and Stoke Mandeville including a Britannia and a Scot.

Aylesbury
With main line trains, local trains to Princes Risborough and Metropolitan services.

The Great Western and Great Central Joint Line
Through Princes Risborough.

Aylesbury to the North
The route through Quainton Road, Brackley to Helmdon Viaduct with a wide variety of steam traction.