I am sure you are familiar with my fascination with underground tunnels etc – and you probably know that in addition to the obvious tube network and municipal services, that there are a fair number of other tunnels under the city.

Some are tiny lines built just below the surface and of no real interest – but there are some whoppers down there and obvious when you think about it, they are rarely named if you ask people to name the tunnels they think are under their streets.

BT have a large network of deep level tunnels which are human sized for their telecoms network – much of it built very deep during the cold war when BT was state owned as a protection against a nuclear strike on the city. The military have a few very old tunnels under Whitehall, and Thames Water famously built their huge ring mains around London in the 1990s.

What about electricity though?

Well, naturally there are cables running under the streets – but high voltage cables cannot be simply buried in a sub-surface structure, but have to be buried deep underground – and in large tunnels with the cables kept separate from each other to prevent overheating. The work on the Stratford site for the Olympics included one such sizeable tunnel to remove all the above ground electricity pylons. The pylons are being removed now that the tunnel is complete – although one will remain, as a visual marker for people to navigate by.

Anyhow – I was researching the recent deep tunnel construction behind Harrods department store recently (I bet that interested you!), and by accident came across reference to the Wimbledon-Pimlico tunnels dug by London Electricity in the early 1990s and been researching that. Some sort of write up might be forthcoming shortly.

I thought I would offer a teaser though – and here is a map from one report published by the Proceedings of ICE I have which shows the layout of some tunnels under the center of London built recently to carry electricity mains. These tunnels are nearly tube sized in width, so they are quite impressive in scale. Its a bit of a pity that they are so little known as they are a very significant engineering exercise.

London Electricity Tunnels


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  1. karen says:

    you know there is supposed to be a buried city under london yes? your writing is not focused and i’m not sure if that is what you are suggesting…

  2. karen says:

    that should be your intro… you are too vague in what you are trying to say. just please tell me you aren’t working towards some academic reward with this website?

  3. IanVisits says:

    It’s a personal blog – not an accademic paper.

    As to a buried city – if you mean archeological remains, then of course I know about them. If you mean a secret city – then sorry, but that is just bunkum.

  4. Smiler says:

    There are a multitude of tunnels under there, with a multitude of entrances – and the MoD ones are not defunct. I know, I wrote the security protocol/procedure for the BT/MoD interface. While this appears on a blog, I will not disclose any sensitive information relating to security, as I’m covered by the OSA for life….. :0(

  5. L Oncle Vanya de Caesaromagus says:

    Secret Tunnesl – is Number 10 and 11 Downing Street connected to ‘safe citidels’ under MoD administrations. Are these tunnels, if they exist recent ones, or were they built during the 1980s when Number 10 came under attack at one point by an IRA mortar attack?

  6. IanVisits says:

    It is not known for certain – but the consensus thought is that there are some old linkages between the buildings built during WW2 as part of the general Cabinet War Rooms and the deep level telecoms tunnel.

    The only 1980s development which is known about is the PINDAR work, which was nothing to do with the IRA, and all about surviving a nuclear war.

  7. Jace says:

    Hiya mate, though id just say (in responce to the first message left on this page) that your writings fine, very intresting and “Karen” seem to a stick up her ass and have quite a few wires crossed! ha. cheers.

  8. lee says:

    Actually there are tunnels leading from 10 downing st to the thames, from the palace to the thames, a tunnel leads from the BBC Radio centre to Admirals arch; and all the tunnels are linked to the War rooms.

    The tunnels were built around victorian times and extended during WWI & further again in WWII.

    They are not vistable by the public as they are escape tunnels for HRH and important VIPs like the PM etc

    Reference the underground city, there are streets built in victorian times that are still visitable by tourists and were just ‘built over’ – there interesting to go see.


  9. IanVisits says:

    There are lots of rumours about such tunnels – but none stand up to much scrutiny.

    While Buck Palace does have a tunnel underneath it – it is actually a sewer, and not usable as an escape route.

    If you have concrete proof, then I will be interested – but I have spoken to a number of officials and read a lot of books on the topic, and ended up being very dubious about many of the claims made on a “nudge, nudge” basis.

  10. peter says:

    all i have to say to all the above there are load of deep level tunnels running all accross the country not just london. i dont know about the theory you all have but i have visited many of these tunnel (for my job) and they aint pleasent and they aint used for no escape route. its next to impossible to just walk through. i really cant see HRH or PM using them. by the way this is my opinion and my 1st hand expreince i may be wrong. and would luv to be corrected with evidence.

    ian you are rite there are tunnels running under buks place and 10 downing street but are just sewage tunnels.

  11. scovic says:

    I know of 1 such tunnel that does exist. It runs from whitehall to charing x & exits by the bakerloo platforms. It would be used to evacuate whitehall in the event of an emergency. it is locked from the whitehall side with no key or any other way of opening the door from the lul side. I know this as I work for lul

  12. IanVisits says:

    The Whitehall tunnel is very well known – as details were published in a Post Office journal in 1946.

  13. Brian Moreau says:

    I am actually going to take photos in one of these tunnels this evening so all will be revealed.

  14. B says:

    I used to work in the BT tunnels when i was an apprentice electrician, we had a contract to fit the tunnels out with flourescent lighting and power points etc. And i can say that the tunnels do travel for miles. I remember going down into the tunnels in the morning at a BT building near Waterloo and coming up for lunch at another BT building situated somewhere around the Strand if i remember correctly.

  15. Martin Gillies says:

    Heya Ian could you tell me what books you read on the topic of secret underground tunnels? thanks.

  16. Paul Yak says:

    Do you REALLY think that ALL these tunnels are to do with utilities. I wish I could tell you, but then you and I would have to be killed (A nods as good as a wink to a blind horse).

    But really, the coincidence of the Water company and the Electricity company building HUGE tunnels around the 90s should give some clue to their real purposes.

    • IanVisits says:

      As the water tunnels are full of water, and the electricity tunnels are carrying electricity, I think their purpose is easy to extrapolate.

  17. Paul Yak says:

    Hi Ian,

    Do you think they would allow us the public, or even you, to know about their underground bunkers, tunnels leading to them etc.

    Where do you think the government, their aids, bodyguards, servants etc will go in the event of a nuclear/biological war?? Stay on the surface like us, I can tell you 100% they will NOT, they will be taken underground via secret tunnels into bunkers to protect them, and they’ll leave us who actually paid for these to be built to perish.


    • IanVisits says:

      Do you think they would allow us the public, or even you, to know about their underground bunkers, tunnels leading to them etc.

      Know about them – not really. Does that mean a large public water rings main that is now full of water is actually a secret bunker? Of course not.

      If you think the government would build “secret bunkers” under London for protection then you need to understand more about the effects of a Hydrogen bomb over a city built on clay.

      The shockwaves would liquefy the soil and any underground structure would at best “sink” and be disconnected from the surface – or more likely, simply be crushed. This is fairly standard knowledge – and is the reason why most people studying this issue dismiss the idea of deep level bunkers under London.

      Obviously, a few sub-surface command bunkers exist for conventional purposes – the most famous being Pindar, but any facility designed to be operational after a nuclear strike would not be based in London. Which is why Burlington wasn’t built in London.

      The Whitehall tunnels appear to have been extended in the early 1950s

      The consensus amongst most people is that they were not so much extended as refurbished and the underground connections to other ministries increased. Indeed, the original southern end is thought to still be unused due to damn problems.

  18. Paul Yak says:

    One pointer works reference 3245 I believe, you won’t hear anything about it until 2020 after 75 years is up, and then only if they feel they have no further use for this tunnel complex.

  19. Paul Yak says:

    The Whitehall tunnels appear to have been extended in the early 1950s. Some official documents refer to a Scheme 3245: this is the only numbered tunnel scheme that has never been officially revealed or located by researchers. Files in the National Archives which may relate to this have been closed for 75 years and will not be opened until the 2020s.

  20. fish says:

    i have only been to bt deep level tunnels. and have been to the whitehall tunnels which have the only toilets in the 27km of bt tunnels. however there are lots of blocked tunnels and shafts. one of which was not on any drawing that we had. if you view duncan cambels pics you will see holes for cabels either side of the door were i found a news paper from 1943. it was by a sealed door which i would love to of known what was on the other side….

    • David says:

      In the second half of the ‘60s and early’70s , I worked for a telephone cable company and also GPO, as BT was then called. Every day I walked miles under central London and the City. We were called cable jointers & testers. I can tell you that there were other toilets down in the deep level, not just Whitehall, one at Holborn, Waterloo, and a couple of others. But if you were caught short it could be a couple of miles to walk. They were all Lead covered telephone and television cables with copper wires inside. I often wonder what those tunnels are like nowadays, now we have fibre optics . Just to say, like the Gentleman before, I am also covered by the official secrets act.

  21. chris says:

    funny enough i just been listening to bbc 5 live were a spokesman who worked for blair when reflecting back openly said there were miles and miles of tunnels built in war time and was extended for far more uses than water and electricity (although the state owned these and would have taken advantage of blurring this). most of these are connected to each other but also go extremely deep under london (four or five levels further than he went when he went down with blair). a nuclear strike would not kill the people down there. and a lot of these spaces underground are also used to store massive amounts of digital data storage and goverment systems protected form outside access, a safe place to be. many of these go deeper than the majority of the underground tube tunnels (possibly excluding Piccadilly) and they are not sewers. these arent exactly secrets, and not surprising. there are also 6 big rivers that flow around and under london which used to see the light of day a long time ago. these are redirected over tube stations etc . there are many books and radio shows dedicated to this subject, but your review seems skeptical. the state clearly take advantage of this. its not like we are talking about ufo’s lol . a great radio phone in on the robert elms show ( LBC) explains about tunnels interconnected (for different uses) which could lead you as far as essex without seeing the sky once. or one of the hundred ghost stations / royal mail lines which you travel past without even knowing it. a good book that comes to mind is i think called underground london.

  22. Rory says:

    I think this is a really interesting subject and would love to find out more. What I find fascinating about this whole thing is that, someone, somewhere must know what is buried under London(with regards to tunnels and other structures, not archaeological remains). Some documents must exist somewhere stating exactly what is under the city and where it is, even if it was to just find out what can be built in the future, as obviously you wouldn’t want to build a tunnel and end up burrowing into something.

    The reason I actually became interested in this was because of a show on BBC called ‘Greatest Cities of the World’. The presenter covered the Chancery Lane tunnels and apparently people who have been down there have heard noise from different parts, suggesting there are potentially other structures extremely close, which I find very intriguing.

    Hopefully someone can shed a little bit more light on the subject as the years tick over!!!

    • Ivor says:

      Chancery Lane is the Kingsway Exchange, and is connected to the Deep Level Tunnel Network. When it’s finally sold, it will be disconnected from the DLTN. Currently a door is all that separates the two.

  23. michael lydamore says:

    Dear sir Well let me see if i can capture your attention I worked for stc north woolwich and albion sugar company. Theres one thing you have on night shift a lot of time on your hands. I and some fellow workers explored the tunnels below what was then albion sugar company. These tunnels run from albion sugar company to 1-greenwich park 2-woolwich arsenal 3-along the river front with access to many buildings and companys.At the time i did some local research and found that alongside the steel building of albion sugar was a older brick and stone building.This was once used as a ships tack supplies etc.a latter use was to ship prisoners to aussie.Works on that building revealed steel rings on the walls that prisoners were attached to. Also on demolition of a internal wall a skelton was found. the tunnels leading to greenwicch were used to move prisoners because of complaints by greenwich residents.Also stc woolich did far more than make telephone cables,I think time has gone by enough to tell of radar delv,there or the vast of londons treasures stored below ground during ww2.After say a year or two we had access to a lot of river front buildings and had a lot of fun leave what must have had others guessing if they had ghosts?. I live in florida and remember well the closing of bot stc and albion sugar. I would like to thank the r.a.c.s. building for there endless supply of razor blades

  24. Minty says:

    Hi Ian,

    Do you know if these tunnels were ever sold? If so, who on Earth would buy them and for what purpose? Thanks!

    • Ben says:

      That’s a great question! Probably some BIG drug dealer… Looking for safer transport etc..

  25. Stevo says:

    Do any of your tunnels go under the Ecuadorian embassy near Harrods??

  26. clive hodgson says:

    i remember back around 1968 when us stockwell kids found a way into the deep air raid shelters under stockwell and south lambeth and clapham roads .
    armed with torches and candles we ventured from the ventilation tower between studley rd and clapham high rd and mapped out the tunnels from kennington through the oval to the vent tower on the roundabout adj to stockwell manor school onto our first entry on studley road then onto clapham north adj to roy riddley ct and onto clapham common then onto balham and tooting bec ending in colliers wood .
    we set up camps and play areas right through the system .
    we had a great time then and the police just gave up trying to chase us as we knew the system so well .
    there was no lights just torches and car batteries linked to 24volt bulbs stolen from buses in stockwell bus garage to illuminate the tunnels .
    thinking back and from a 57yr old grandparents perspective we must have been nuts .
    but they were happy days and we thought we were invincible .

  27. Phil Carter says:

    Hello all,

    I am fascinated by this set of postings.. thank you all.
    I wonder if someone can answer somnething for me? My father told me way back in the 1960’s that somewhere under London, he did not know where, are many many rooms housing much documentary record and archives, relating to both Government and both Met and City Police records.
    Is this true? And if true, how in heaven’s name does one go about trying to get permission to search these archives?

    • IanVisits says:

      The National Archives is open to anyone to visit – it’s in Kew.

      The Met Archives of the City of London likewise.

      There are no “secret rooms” involved.

  28. Phil Carter says:

    Hello Ian,

    Thanks for the reply.

    Yes, I am aware of all of these archives. Have been to them all.
    I did not think there were any secret rooms or suchlike at these establishments..but my point was something my father told me way back in the 1960’s. He worked for the Home Office for a period of time, and was closely involved in Government work before that, during WWII.

    That is where the comments came from. ..and consequently wondered if any others had heard of the proposed archive chambers under London.
    From my recollections, and I admit they are hazy, he mentioned a few times as we drove through town, of the chambers beneath the streets. Only in later life have I actually paid attention to the comments.

    From my own personal searches, many documents from the DPP have either gone missing” or have “b
    een destroyed.”

    • IanVisits says:

      The only others would be the private document storage companies who use old WW2 shelters as short term storage for some files.

      The blunt fact is that London’s geology means that underground storage is a bad idea within London. All the large underground storage facilities are outside London – because of the geological problems here.

      Most rumours of deep level structures fail the geology test.

  29. Alf memory says:

    Being a much younger man then most that would be interested in such things as tunnels under london then most,A.D.1970. Im going to share something that i dont think most people would care to know …. I was brought up in the wembley area N.W.10
    As a child i used to play around the river brent and used to go onto railway property, I did so on a regular basis and found a tunnel that went from the bottom of blackbird hill under wembley stadium, It’s not documented anywhere.This is interesting as it is constructed as a railway tunnel but has no ballast… just soft sand, at the other end there is a blast door as i remember a door that has a wheel lock mechanism. .

  30. Andy Jenner says:

    Back in the mid 90s I was working in Marsham Street as an electrician. The department of transport was occupying the three tower blocks, two of which were built on rotundas which were left over from an old gas works site. These rotundas had been formed into three levels which were accessed by huge blast doors. On the middle floor there is an interlinking passage between the two rotundas, and this is where it gets interesting.
    One day the facilities manager had asked us to fit some emergency lighting in a stair case. We was lead to the central passage between the two rotundas and in the middle was a non descript door which opened into a room with a small one man lift (which didn’t work) and a spiral staircase. This stair case went down at least 100 ft eventually opening into a tunnel. This was locked with a metal barred gate. Armed with a spanner it was quite easy to undo the hinges and get into the tunnel. The tunel was being used by BT and had lighting which disappeared into the distance. At this point I lost my nerve and locked it back up.

    • Daniele Mandelli says:

      Andy, great read.

      I think this is the site of the new Home Office building. The tunnel did indeed reach there from QEII conference Centre. I recall seeing a photo of a door on Marsham Street where access to the tunnels is now made since the old DoE and Rotundas have been demolished.

    • Kevin Jones says:

      I heard about the tunnel with the barred gate from friends on the DETR security staff when I worked there, and about the tunnel between the two rotundas.

      However, what was *under* the rotundas is still there, and goes down several levels. They only took off the rotundas and the next level down. Access to what remains (another 4-5 layers according to folks in security) is, on the Home Office site, now restricted nto a single lift from the Ministerial floor that is reserved for Ministers. There is no other access from the Home Office site, since the rest of whatever is down there is sealed off by a thick reinforced concrete pad that serves as the foundation for the building.

      How do I know? Simple. I worked opposite and had a window seat. I therefore had a grandstand view, every day, of them demolishing Marsham Towers and building the new Home Office building. 🙂 I found it fascinating. From what I saw of the comings and going to the lower levels – via an opening left for the purpose and later sealed prior to pouring the thick reinforced concrete pad – they would appear to have refurbished whatever is underneath the new building.

      Home Office staff refer to it as ‘the bomb shelter’. If the concrete that it is made of is anything like the concrete used to make the bits they demolished, it is exceptionally tough. They had to use explosives and very heavy blast blankets to make enough of an impression for the demolition machines with their jaws to be able to get to work, and even then it took a lot of work with the explosives. The work went on for ages. I was fascinated by the flash of light from the detonating cord that zipped round the site whenever they set off the explosives. I did wonder if they were going to continue all the way down, or whether they were just going to pour concrete into the next level below those that they had demolished. However, they got increasingly careful as they got down lower, and it soon became apparent that they were going to preserve the lower levels. Then they covered the lot with a thick pad, except for what became a lift shaft.

  31. frosty says:

    This is a good read, mainly for the comments! ;). Sounds interesting andy jenner! Ive never really done anything in london except clapham north, there is a seriously IMMENSE amount of stuff around to look at,most of which comes up with a quick tap on google on a night shift! ;D. Cheers guys.

  32. B says:

    At the corner of Oxford Street and Dering Street there was an extensive reconstruction work for the retail outlets. When they were digging out the foundations they found a bunker which wasn’t on any map or record. They sounded it and found the walls were at lest 1m thick. There was no entrance but as it ran under Other buildings they couldn’t easily explore further. They tried to drill in but even with heavy rigs they didn’t get far and gave up. They just built the foundations on top of the structure and let it be.

    Lord knows what it was but probably some lost legacy of the cold war.

  33. stephen says:

    Working in Lambeth with the long term homeless im hearing some incredible stories about life underground. If you are interested please reply. I am the ultimte sceptic but backed up stories put the
    wind up me.

  34. paul burchell says:

    the tunnel under Whitehall extended from Marsham Street all the way to Holborn & connect with/into the BT complex under Holborn

    • IanVisits says:

      No – it did not.

      Read the article again.

    • Daniele Mandelli says:

      A tunnel is a tunnel to most. The Whitehall tunnels end short of Trafalgar square and are sealed off from the BT tunnels which do indeed extend north from there to Holburn and other areas. There is a photo of the door to Whitehall area.

  35. dave says:

    Are you sure 😉

  36. Daniele Mandelli says:

    Have often been curious about the Pimlico – Wimbledon electricity tunnel, as I used to live in Wimbledon.
    Where is the Wimbledon end? I guessed near Dunsford Road and the electric substation there?

  37. happy says:

    daniele, here is the wimbledon end, stick these numbers in GE 51° 25.941’N, 0° 11.311’W


    • Daniele Mandelli says:

      Hi Happy

      Just found this after not looking here for months!
      Will do. Thank you

  38. happy says:

    funny thing is and for all the conspiracy theorists, the wimbledon pimlico tunnel passes a few yards from the new US embassy. Is that a joeincidence?-)

  39. DP says:

    I’m fascinated by some of the comments and information here.

    I often work at the QE2 Conference Centre and there have been many rumours about the tunnels linking it to Whitehall and Parliament.

    We’ve got access down as far as -3 (-1 is car park and plant, -2 is offices, old TV studios and stores, -3 is just a huge storage area and the Parliamentary Library, which we don’t have access to).

    There lots of rumours about how far down the centre goes, some say it goes as far as NINE floors below ground. It’s a pretty common “rumour” that -4 is an old GPO telephone exchange, so it makes perfect sense that there is (or was) access to the Deep Level Tunnels.

    I’d love to find out more but don’t want to arouse suspicion!

    • Daniele Mandelli says:


      Have you had a look at the 2 shafts on the lawn outside the building?
      The one furthest east is some sort of emergency exit. I stuck a camera in the grill once and took several shots and it showed a stairway down with handrail and sign that the stairway is alarmed. This is at foot level so you have to get right down to see.
      Probably as alarmed as the Japanese tourists were of some bloke on his knees peering into a small opening.
      A 1980 cabinet office document I found on the internet made mention of – ” secure telephone exchanges ” and “other installations which we cannot move” so there is certainly something down there. I also read the current telephone exchanges of certain government departments and the House of Commons is there but who knows?

    • Martin Swai says:

      I used to work for ITN, they used one of the -2 levels TV studios as their Westminster Studio in the 80s. The BBC used the other one. The studio itself was double height so cut up into level -1. I didn’t visit often, and one day got out of the lift at the wrong level (I seem to recall that the floors available went to -4). Anyway I was met by an armed guard who suggested I had made a mistake….. which I had of course.

      Earlier this year I had to visit the QE2 on a project which I cannot talk about. But we had to visit the comms room, which I think was on -3. No armed guard….. so maybe the secrets are no longer sensitive! The comms room was interesting… lots of very old BBC video circuit equipment from analogue days, but still powered. Also a huge number of analogue telephone and possibly program circuits on Krone frames. I cannot believe that the conference centre still uses analogue internal communications. So what does everything do? Anyone have any

    • Martin Swain says:

      I used to work for ITN, they used one of the -2 levels TV studios as their Westminster Studio in the 80s. The BBC used the other one. The studio itself was double height so cut up into level -1. I didn’t visit often, and one day got out of the lift at the wrong level (I seem to recall that the floors available went to -4). Anyway I was met by an armed guard who suggested I had made a mistake….. which I had of course.

      Earlier this year I had to visit the QE2 on a project which I cannot talk about. But we had to visit the comms room, which I think was on -3. No armed guard….. so maybe the secrets are no longer sensitive! The comms room was interesting… lots of very old BBC video circuit equipment from analogue days, but still powered. Also a huge number of analogue telephone and possibly program circuits on Krone frames. I cannot believe that the conference centre still uses analogue internal communications. So what does everything do? Anyone have anything to add?

  40. Ray Cutler says:

    Reading the comment about the Oxford Street/Dering Street junction, here is another one to add to the collection.
    About the end of the ’70’s I was talking to a sparky who worked on a job under M&S in Oxford Street/Orchard Street. He told me that this was a fall out shelter but that is as much as I knew.
    I’ve looked it up but can find no mention of it anywhere.
    I guess an email to M&S might provide the answer but I seriously doubt it.
    If it did exist, could it of provided a shelter/back up facility for it’s (then) Back Street hq?

  41. Richard says:

    Fascinating stuff, thought I would add my t’penny worth. When I was a child I was fascinated by the London underground. My uncle worked for BT and I remember when I was a kid he told me that he had been working on a telephone exchange in London which was deeper than the tube (I presume he meant the Kingsway exchange), he also told me that there were miles and miles of BT tunnels under London (obviously true), and he told be he could have walked from Kingsway exchange to my Nan’s house near Clapham Common through these tunnels.
    Now looking back I am sure that he was just trying to impress his wide eyed nephew, appearing as a really cool uncle, with his tale of walking to Clapham Common in the BT tunnels, but I saw a YouTube vid of urban explorers in the Clapham Common deep level shelter, and one of them mentioned that it is linked to the BT tunnels. So, do you know if it is? I suspect not, and my uncle was just exaggerating to an impressionable 10 year old.

  42. Jay Dubya says:

    I worked in the tunnels, going down at BT Tower and was clearing asbestos… I also went down at Kingsway and covent garden… There are miles of tunnels of cables and multiple shafts

  43. John R says:

    Does anyone have any information on the BT tunnels in Judd Street underneath the Openrach offices. Particularly interested in how deeep they are and whether any plans are in the public domain

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