stignest wrote:The cairn doesn't seem to have any antiquity about it and as its not on any of the main routes up to Pole Bank the liklihood of being challenged would surely be minimal. Have any other members had issues in the past when disturbing cairns? Is there any just reason some bod could have a go? - especially in light that on Cadair Idris they are pulling cairns down.
Yearlet is a fairly popular hill I think, more so at weekends perhaps. The cairn is a large pile of quite small stones, but reviewing the photo
http://trigpointinguk-photos.s3.amazonaws.com/129/P129642.jpg it's not exactly shapely. If challenged I'd just say you're searching for the trig point (have a copy of something vaguely official such as the TPUK page?) and will rebuild the cairn afterwards. Take something to probe with (18 inch screwdriver works for me, well sometimes) and at least a trowel.
In less popular places I've dismantled plenty of cairns, rebuilding / relocating them afterwards, and never seen anyone. At one site down south there was a no digging sign; fortunately found nothing to dig for.
I guess you maybe ought to check with the National Trust if it's their land. They can only say no (and maybe would, as their record with trigs isn't good).
It occurs me this isn't the easiest choice for your first surface block hunt

And there's a fair chance you'll find nothing. Or that it's buried near to the cairn, or destroyed.
Anyway, good luck!