Highgate High-Level

Early railways had bypassed the high ground to the North of London (known as the Northern Heights) but in the 1860s the Edgware, Highgate & London Railway was formed to link Edgware, Mill Hill, Highgate and Finchley to London via Finsbury Park. The scheme was taken over by the Great Northern Railway during building and the line opened in 1867 [1].

Type: Great Northern Railway 
Opened: 1867
Closed: 1954
Platforms: 2
Highgate station was opened in 1867, the station located in a small cutting with the railway entering tunnels either end of the platforms. The station originally had 2 separate platforms but was later modified to have an island platform to aid interchange between the various services that called at Highgate including to Alexandra Palace, a branch line opening in 1873.

As part of the pre-Second World War New Works Programme London Transport extended the Northern Line out to Highgate and beyond with the new tube station built underneath the existing Highgate station [2] - the Northern Heights Plan [3]. Highgate was intended to become a major transport hub in the North of London integrating surface and tube services with a Charles Holden designed rebuilt Highgate High Level. The Second World War interrupted these grand plans though Highgate tube station was able to open in 1941 [4]. Any other work was cut back and suspended.

After the end of the war austerity and new laws protecting the Green Belt saw the railway plans for North of London cut back dramatically. Highgate High Level began to decline after plans to rebuild the station were abandoned. The Alexander Palace branch was closed in 1954 and with it passenger services to the High Level station [5]. The line continued to be used by freight but the rails were finally lifted in 1971.

Highgate High Level didn't disappear however. The site was gradually reclaimed by nature and is now a valuable nature reserve. The tunnels have become a bat sanctuary. The platforms and some station buildings have been retained and are sometimes used for filming and tours.
Surviving platform structures

The track bed is now covered over 
Former booking office and station house

Subway access

Entrance to one of the tunnels, now for bats only!

Surviving infrastructure, old and newer!

[1] Siddy Holloway, Highgate wilderness walkabout (London Transport Museum, 2017) p. 3
[2] Paul Moss, London Underground (Haynes, 2014) p. 94
[3] Holloway p. 8
[4] Jason Cross, London Underground Guide 2017 (Train Crazy, 2017) p. 132
[5] Ben Pedroche, Do Not Alight Here (Capital History, 2011) p. 99