Elstree South tube station

Elstree South
Elstree South Location of Elstree South in Hertfordshire
Location	Elstree
Local authority	Hertsmere
Grid reference	TQ175946
Number of platforms	2 (planned but not built)
Railway companies
Original company	London Underground
Other information
Lists of stations	DLR Underground National Rail Tramlink
WGS84	51°38′17″N 0°18′13″W / 51.63794°N 0.30349°W / 51.63794; -0.30349Coordinates: 51°38′17″N 0°18′13″W / 51.63794°N 0.30349°W / 51.63794; -0.30349

Elstree South (usually just Elstree on Underground maps) was a proposed London Underground station in Elstree, Hertfordshire. It was designed by Charles Holden. The planned location of the station was adjacent to the A5183, north of the junction with the A41 and where junction 4 of the M1 motorway was subsequently built.

The station was the second of three planned by London Underground in 1935 for an extension of the Northern line from Edgware to Bushey Heath.

The extension was part of the Northern Heights project which was intended to electrify a number of steam-operated London and North Eastern Railway (LNER) branch lines and to incorporate them into the Northern line. The powers to build the extension came from the purchase in 1922 of the unbuilt Watford and Edgware Railway which had planned an extension of the Edgware, Highgate and London Railway to Watford Junction via Bushey, but had never been able to raise the capital required for construction to start.

Construction works on the Northern Heights project began in the late 1930s but were interrupted by the outbreak of the Second World War. Most of the work undertaken to that date had been carried out on the existing LNER branch tracks but some work between Edgware and Elstree had taken place. Land had been purchased along the route of the new rail line and some earthworks had been constructed. North of Brockley Hill station a pair of 500m tunnels were partly constructed through a hill towards Elstree. The northern tunnel mouths would have opened immediately before the station. Also adjacent to the site the carriage depot for the line was completed in 1939 but during the war it was converted to use as a munitions factory. After the war it became Aldenham Bus Overhaul Works until it was closed in the 1980s and demolished in the 1990s.