London’s invisible lines: The Boundary Marker File

In the course of our attempts to catalogue London’s inter-dimensional gateways, PoL has learned to keep an open mind. The unpredictable happens when a Londoner treads too close to the city’s precarious dimensional bounds. We are accustomed to the scattershot nature of the resulting stories.

But it seems we may not be the first to try to impose a sense of order on this chaotic history.

Image by Graeme Duckworth  (CC BY-SA 4.0)

The boundaries within what PoL terms ‘base London’ can be slippery enough, vulnerable to the whims of restructuring governments or other quirks of history. But that doesn’t stop attempts to set them in stone. Plaques, posts, and kerbside markings can be seen all over the city, manifesting the often invisible lines between parishes and other entities.

For example, the boundary between Hammersmith and Fulham parishes, once marked by a now lost irrigation known as Parr’s Ditch, is carved into tide-weathered stone where the ditch once entered the Thames (the plaques read H.P. 1865 | F.P. 1865):


It isn’t just the initials of neighbouring parishes that are etched around the city. More obscure symbols may represent historic Guilds with administrative powers over an area.

The photo below left was taken by George Sandeman, who forwarded it to us via Twitter. George found these markings on a kerb in Soho, close to a more traditional boundary marker.

Below right shows a post-type marker from Sydenham Hill, at the borders of Lammas Green, one of a number of Corporation of London estates that can be found far from the geographical constraints of the Square Mile.


But it is the possible existence of a set of still stranger markings with which this post is concerned.

A friend of PoL’s, Iqbal Mahmud, has been in touch, to tell us of a file he discovered in a neglected corner of the City of London archives, while he was investigating the strange instances around the Black House.

The file, says Iqbal, comprised several sheets of paper, and about 10 to 15 photos.

“I didn’t think much of it at first. The words ‘Black House’ got my attention. But I couldn’t make much sense of it after that”.

He copied the relevant page into his notebook, and put it out of his mind. But in the months since, it has crept back into his consciousness. And Iqbal has come to believe that what he discovered is very important indeed.

To someone.

A section of the 1666 map that some say shows the Black House

The page that mentioned the Black House appeared to show a kind of key, comprising a long list of obscure symbols – with text next to each symbol apparently denoting its meaning.

“I asked the clerk about it – he didn’t know what it was. He called a superior over and she didn’t know either”

The superior made a phone call, but whoever she spoke to was of little help. Iqbal went back to his table, made a quick copy of the page, and finished up his research for the day, placing the Black House files back on the shelves where he found them. He never saw them again. Nor has he found anyone who will admit to knowing anything about them.

Iqbal says it seems obvious now. “That was the moment, asking about that one file. Like, someone in there realised what I had, realised what I was on to, and then the files disappeared”.

This is our sketch of the symbols Iqbal copied down, with the meanings assigned to them shown in corresponding grid format below:


Screen Shot 2018-04-01 at 18.12.49

And then there were the photos.

Black and white prints – Iqbal reckons they dated from around the 1950s – artless and functional, the kind of thing a surveying official might make. They appeared to show examples of the markings in situ – on kerbs, above doorways, placed in brick walls. Frustratingly, the images were close-up. Iqbal doesn’t recall any features that gave away a specific location.

What he’s sure of is that the document he saw was the key for some kind of marking system, and that at least some of these symbols are, or once were, etched on to streets around the city.

Are they boundary markings? The presence of the Black House on the list would suggest that if so, then it could be dimensional boundaries they are attempting to mark.

But who made them?

And do they simply represent a desire to describe known phenomena? Or are they an attempt to exert some form of power or control over London’s doorways?

These are questions to which PoL will return.

Addendum: Graham Herod, a former City of London tour guide with a growing interest in London’s portals, (and a special interest in the Church of All-Corners-Within-The-Wall) tells us he has seen no such symbols in his many years walking London’s streets. 

Featured image : Ogilby and Morgan map (public domain)

2 comments on “London’s invisible lines: The Boundary Marker File

  1. Cargo Cult

    By some eerie coincidence, the page I had open immediately before seeing a new Portals of London post in my RSS reader was this one:

    (I was trying to figure out the meaning of some odd boundary markers on the 1/2500 scale maps I’d been was looking at. Haven’t spotted any other Black Houses yet.)


    Liked by 1 person

  2. Joel Barr

    Seems like an exceptional amount of conjecture in this post, but I look forward to hearing more about the Black House


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: