I'll settle for a general description for this one (e.g. the wall between abc and xyz or the path leading to *** ... you get the idea :-D ) as I'm not sure its location actually has a place-name as such!
Ooh ... don t know this one at all ... blue elvan walling as well, that must have taken a bit of breaking and building; I see the age old tradition of the bitmac paving has spread in its cankerous way; A King George marker, no less. Older than me, just.
We used to have something called Post Office Telephones; these marked the main lines underground - there is more, but I have not managed to research any of it; The one which preceded all of that system in these ere parts was that by The Western Union Telegraph Company. Progressivly these are being removed or buried in bitmac (or previously tarmac).
I have a thought that they may have been a part of the Surveying system, as some are marked with what appears to be a Bench Mark marker, where the bottom has not been obscured by fill. The panel above that was marked with the depth at which the cable ran. I think the numbers were of a form of aluminium casting, or a tough bakelite in some cases.
I ve wondered about the benchmark symbol on these, too, but I thought the numbers referred to the location of a nearby inspection chamber, eg for a coupling - maybe this is only the case with the later concrete models?
If it was a distance marker (for those that are unable to see the cover right under their HSE noses) it would have to have a direction mark as well, a form of Cartesian Coordinate.
