On 22 June 1907 the Charing Cross branch of the tube opened.
An estimated 127,500 people took advantage of the free fare on opening day.
This photograph was taken near Golders Green tube station, which was the terminus of the line.
Until the tube was built, Golders Green was almost completely rural.
Easier transport led to many housing developments going up in the area very soon thereafter.
The Northern Line was extended to Edgware in the early 1920s.
The description opposite reads: "Yesterday important alterations for the accommodation of holiday traffic at Hampstead Heath Railway Station..."
The station is on the Edgware branch of the Northern Line, between Golders Green and Belsize Park stations, and on the boundary between Travelcard Zone 2 and Zone 3.
The station was opened on 22 June 1907 by the Charing Cross, Euston & Hampstead Railway.
Located at the junction of Heath Street and Hampstead High Street, the name Heath Street was proposed for the station before opening.
Indeed, the original tiled station signs on the platform walls, recently restored, still read "Heath Street".
Hampstead is on a steep hill and the station platforms are the deepest on the London Underground network, at 58.5 metres or 192 feet below ground level.
It has the deepest lift shaft on the Underground at 181 feet. There is also a spiral emergency staircase, made up of over 320 steps.
To the north, between Hampstead and Golders Green stations is the uncompleted North End or Bull & Bush
Hampstead Heath station on the North London Line is a 10-15 minute walk