Dover is only a 30 minute drive away for me, so I've walked this section of the North Downs Way many times - the clifftop path over Shakespeare Cliff between Folkestone and Dover is one of my very favourite places.
One day, as I was passing, I noticed a trig pillar that for some reason I'd not noticed before. Probably for the very reason that it's easily missed - and also because it stands just a couple of feet from a 400 ft drop on a crumbling cliff edge - this is my very favourite trig pillar!
Bag it while it's still there!