In various parts of London and in many other English cities kerbstones bear enigmatic markings. This kerbstone code has yet to be deciphered.

London is a great place to visit for everybody interested in crypto history. Not only are there several London-based museums exhibiting crypto items, but also a number of archives and libraries have interesting material. And, of course, nearby Bletchley Park is a must-see for every crypto history enthusiast. It therefore comes as no surprise that my cryptologic travel guide (co-created by Christian Baumann) lists over a dozen places worth seeing in London.


The kerbstone code

Although I have been in London many times to visit all these interesting places, there seems to be one thing I have missed so far: the kerbstone code. Thanks to George Keller for informing me about this mystery.

London-Curbstones (4)

Kerbstone marks, usually consisting of simple geomatric shapes, can be seen in various parts of London and in many other towns and cities in England. Though there are quite a few websites about this phenomenon, introducing many hypotheses about the origin and the meaning of this code, no generally accepted explanation exists.

Apparently, the marked kerbstones stem from the Victorian era. Some of the marks seem to have been carved in the kerb after laying. It is hard to examine if the code had some geographical meaning (e.g., indicating the location of something), as many Victorian kerbstones are not located at their original positions any more (when a street was reconstructed, the kerbstones were often reused at a different place).

London-Curbstones (6)

Here are a few potential explanations of the code that have been put forward:

  • The signs might be service marks for the electricity, gas and telephone companies.
  • At least some of the symbols might mark borough boundaries.
  • The symbols could be stonemason’s marks.
  • The marks might indicate the location of war time utilities, such as water hydrants and bomb shelters.
  • Perhaps, the whole code is a hoax created by Victorian road workers.
  • As some of the stone masons were hard labour convicts in prisons, the symbols might be part of a prison inmate code.
  • As it certainly happened that curbstones were stolen, the symbols might have marked the legitimate owner of a stone.

It is well possible that the real explanation of the kerbstone code is a combination of several of these theories.

London-Curbstones (3)

Additional research needed

If you want to know more about the kerbstone code, check one of the websites about this topic. The most comprehensive one is titled Cracking Britain’s Kerbstone Symbol Code. It was made by Scottish historian, author and documentary filmmaker Ashley Cowie.

London-Curbstones (5)

According to Cowie’s site, a US artist named Lauren Drescher has written a research paper about the kerbstone symbols. I can’t find this paper anywhere, maybe a reader can help. Apart from this, I am not aware of a scientific publication about this code. It is not mentioned in the crypto history literature I know (maybe because the code is not cryptologic in the narrow sense).

If you know more about this kerbstone code, please let me know.

Further reading: Sherlock Holmes and the Pollaky cryptograms


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Kommentare (7)

  1. #1 Gerry
    1. November 2017

    At least in Newcastle they used to mark the position of underground power cable joints, as there often were cable faults (see last comment from Stafford Linsley):
    Peter Dolan has found four different types of marks, parish boundaries, borough maintenance boundaries, government property and service marks for elecricity, gas, water and telephone:

  2. #2 Seth
    2. November 2017

    I have those in my city, they are surveyor marks. You can find them in the woods around New England as well on large rocks, often at the corner of stone walls, i think they date from colonial times. Where a stone wasn’t available they would bury up to its top a granite pier many feet tall and drill a small hole in it.

  3. #3 Silur
    2. November 2017

    In Vienna these are called “Zinken”… Signs of vagabounds indicating..shelter..warnings..hospitality..etc…
    Sociologist Roland Girtler wrote a Book on those people..
    But I cannot be sure about it in the UK of course

  4. #4 Benni
    5. November 2017

    Sieht aus wie Gaunerzinken.
    Aber in Stein gemeißelt machen die irgendwie keinen Sinn.

  5. #5 Breaker
    6. November 2017

    I find it unique that these are known both to be marks of particular Masons who laid them, as well as the fact that being in london that they also bear the marks similar to some of the marks found on stones on Oak Island… particular….the H+O Stone……

    These marks on the H+O Stone can be found here:

    and here:

  6. #6 Hias
    6. November 2017

    Möglicherweise handelt es sich um Steinmetzzeichen.

  7. #7 Alistair
    6. November 2017

    Hello, I’ve written a blog post that covers this in more detail and has links to other journals that have interesting info on it as well. Gerry has kindly mentioned the link above, but here it is again:
    We have surveyor’s marks similar to the ones Seth describes in the UK, but they are usually on higher ground and do not repeat in a small area – these are definitely a different thing. They are also not ‘Zinken’- carving a symbol into a kerbstone made from tough rock would take too long and attract too much attention. Drescher’s idea of the plague memorials is romantic but wrong. Similar symbols appear on kerbstones in cities all over Britain, including on streets that weren’t constructed at the time of the plague.
    I used to think, like Ashley Cowie, that they were mason’s marks but am now convinced that they are marking utilities connections underground. Stafford Linsley’s excellent comment on my blog post (also mentioned by Gerry above) has pretty much answered the conundrum for me.
    All the best,