TrigpointingUK

On the flush brackets on trig pillars are two holes or indents above the benchmark. Can anyone shed light on these and what they are for?
I've searched most descriptions but they are not mentioned.

Excellent many thanks. I'm going to try and visit a couple of those.

I came across this trig TP4885 Monk Bretton which is decorated as Stan the Minion.
If you know of any more that are decrated can you add to the list, thanks.

TP4885 Monk Bretton - Minion
TP4079 Hurlet Hill -Alien

Thanks for that.

I came across a pic of a pillar that had an 'alien' as graffiti.

Does anyone know where it is located ?

There's a trig local to me that is/was in the sports field of a school.
The school has been demolished and the land sold.
Now the builders are in the process of creating a new housing estate and are about 200m from the trig, which is stood all on its own in the field. It has views to the south ...

A bit late to answer but another way to show the trigs is via Google Earth using a kml file.

I have the 10km squares and the trig pillars as a selectable overlay for Earth. I can select just square SK79 say and show all the trig pillars in that square, Sometimes zooming in you can just visually ...