-
Difficulty:
-
-
Terrain:
-
Size: 
(micro)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
A cache on the footbridge over the Northern Line depot at Morden.
This location marks the southernmost point on the London Underground network, just south of Morden station on the Northern Line (which doesn't go the furthest North!).
History of the Northern Line
The core of the Northern line evolved from two railway companies: the City & South London Railway (C&SLR) and the Charing Cross, Euston & Hampstead Railway (CCE&HR).
The C&SLR, London's first deep-level tube railway, was built under the supervision of James Henry Greathead, who had been responsible, with Peter W. Barlow, for the Tower Subway. It was the first of the Underground's lines to be constructed by boring deep below the surface and the first to be operated by electric traction. The railway opened in November 1890 from Stockwell to a now-disused station at King William Street. This was inconveniently placed and unable to cope with the company's traffic so, in 1900, a new route to Moorgate via Bank was opened. By 1907 the C&SLR had been further extended at both ends to run from Clapham Common to Euston.
The CCE&HR (commonly known as the "Hampstead Tube") was opened in 1907 and ran from Charing Cross (known for many years as Strand) via Euston and Camden Town (where there was a junction) to Golders Green and Highgate (now known as Archway). It was extended south by one stop to Embankment in 1914 to form an interchange with the Bakerloo and District lines. In 1913, the Underground Electric Railways Company of London (UERL), owner of the CCE&HR, took over the C&SLR, although they remained separate companies.
During the early 1920s, a series of works was carried out to connect the C&SLR and CCE&HR tunnels to enable an integrated service to be operated. The first of these new tunnels, between the C&SLR's Euston station and the CCE&HR's station at Camden Town, had originally been planned in 1912, but had been delayed by World War I. The second connection linked the CCE&HR's Embankment and C&SLR's Kennington stations and provided a new intermediate station at Waterloo to connect to the main line station there and the Bakerloo line. The smaller-diameter tunnels of the C&SLR were expanded to match the standard diameter of the CCE&HR and the other deep tube lines.
The engineering of the Morden extension of the C&SLR from Clapham Common to Morden was more demanding, running in tunnels to a point just north of Morden station, which was constructed in a cutting. The extension was initially planned to continue to Sutton over part of the route for the unbuilt Wimbledon and Sutton Railway, in which the UERL held a stake, but agreements were made with the Southern Railway to end the extension at Morden. The extension opened in 1926 with seven new stations, all designed by Charles Holden in a modern style.
With the exception of Morden and Clapham South, where more land was available, the new stations were built on confined corner sites at main road junctions in already developed areas. Holden made good use of this limited space and designed impressive buildings. The street-level structures are of white Portland stone with tall double-height ticket halls, with the famous London Underground roundel made up in coloured glass panels in large glazed screens. The stone columns framing the glass screens are surmounted by a capital formed as a three-dimensional version of the roundel. The large expanses of glass above the entrances ensure that the ticket halls are bright and, lit from within at night, welcoming.
The first and last new stations on the extension, Clapham South and Morden, include a parade of shops and were designed with structures capable of being built above (like many of the earlier central London stations). Clapham South was extended upwards soon after its construction with a block of apartments; Morden was extended upwards in the 1960s with a block of offices. All the stations on the extension, except Morden itself, are Grade II listed buildings.
Although other London Underground lines operate fully underground, the Northern line is unusual in that it is a deep-level tube line that serves the outer suburbs of South London yet there is only one station above ground (Morden tube station) while the rest of this part of the line is deep below ground. The short section to Morden depot is also above ground. This is partly because its southern extension into the outer suburbs was not done by taking over an existing surface line as was generally the case with routes like the Central, Jubilee and Piccadilly lines. Apart from the core central underground tunnels, part of the section between Hendon and Colindale is also underground.
The tunnel from Morden to East Finchley via Bank, 17 miles 528 yards (27.841 km), was for a time the longest in the world. The Seikan Tunnel is now longer.
You are looking for a magnetic micro sized container.
Additional Hints
(Decrypt)
sbhegrra
Ab cubgb ybtf cyrnfr, vs lbh qba'g unir n cra.... obeebj bar!