Just been downta Lands End, and visited the Men-an-Tol, which as we all know has the same kinda healing properties.
You have to pass your kiddies through it NINE times (oh fuck, here we go again), or crawl around it nine times to work its magic.
At the Men-an-Tol, radiation in the hole is twice that of the environment. Which is Odd in the general sense, but apparently very common with holed stones.