Some years ago, maybe 20 or more, the Ordnance Survey started desmantling the trig points (they've not been needed for surveying for a good long time with aerial photography and sattellite imaging). One of my favourites, on top of Pen-y-Fan in South Wales, was an early victim and I mourn it's loss whenever I walk the Brecon Beacons ridge. Fortunately, they listened to the clamour of dismay from walkers and stopped the programme, and instead sought people to adopt them. Not sure what happened thereafter, but they're still a feature of the UK landscape thank goodness.
I like the idea of a moonlit pose by the trig point on Arthur's Seat some time, and I'll hope to acquaint myself with a few more naked concrete pillars this summer.