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. History Planning and construction The station was the second of three planned by London Passenger Transport Board (LPTB) in 1935 for an extension of the Northern line from Edgware to Bushey Heath. There was debate about the name for the station, with Elstree Hill and Elstree being proposed. 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. Much of the land for the extension came from the purchase in 1922 by the LPTB's precursor, the Underground Electric Railways Company of London, of the unbuilt Watford and Edgware Railway (W&ER). The W&ER had planned an extension of the Edgware, Highgate and London Railway to Watford Junction via Bushey, but it had never raised the capital required and its powers to construct a line had expired in 1911. The specific route to Bushey Heath was approved by parliament in October 1937. The LPTB's principal purpose for the extension to Elstree was to stimulate the development of new residential areas to increase passenger numbers. A secondary purpose was to provide a location suitable for a large new depot that was required to accommodate and maintain the new fleet of 1938 Stock trains to be used across the existing Northern line and the lines taken over from the LNER. Elstree South station was to be located in a cutting with the platforms immediately north of the portals for a pair of long tunnels through a hill towards Brockley Hill. Immediately north of the station were the junctions to the depot and a pair of depot sidings would have occupied the station cutting on the south side. The station building, designed by Charles Holden, would have had a statue of a Roman Centurion at one end reflecting, inspired by the nearby site of the Roman settlement of Sulloniacae. As part of the station works, the road in front of the station, Elstree Hill (now Elstree Hill South), was to be widened to to accommodate a planned trunk road