Twelve O'Clock Rock (as it is named on the OS sheets) also somewhat dominates the skyline eastward across St. Ives Bay, and despite its relatively diminutive size, can easily be picked out from the barrow at Godrevy, over 9km away.
Hunt quotes O Halliwell's 'Rambles in Western Cornwall, by the Footsteps of the Giants' - the giants were always entertaining themselves with 'bob buttons' and other ball games using rocks.
"Doubtlessly the Giant's Chair on Trink Hill was frequently used during the progress of the game, nor is it improbable that the Giant's Well was also in requisition. Here, then, were at hand opportunities for rest and refreshment--the circumstances of the various traditions agreeing well with, and, in fact, demonstrating the truth of each other."
Numbers of people would formerly visit a remarkable Logan stone, near Nancledrea, which had been, by supernatural power, impressed with some peculiar sense at midnight. Although it was quite impossible to move this stone during daylight, or indeed by human power at any other time, it would rock like a cradle exactly at midnight. Many a child has been cured of rickets by being placed naked at this hour on the twelve-o'clock stone. If, however, the child was "misbegotten," or, if it was the offspring of dissolute parents, the stone would not move, and consequently no cure was effected.
On the Cuckoo Hill, eastward of Nancledrea, there stood, but a few years since, two piles of rock about eight feet apart, and these were united by a large flat stone carefully placed upon them,--thus forming a doorway which was, as my informant told me, "large and high enough to drive a horse and cart through." It was formerly the custom to march in procession through this "doorway" in going to the twelve-o'clock stone.
The stone-mason has, however, been busy hereabout; and every mass of granite, whether rendered notorious by the Giants or holy by the Druids, if found to be of the size required, has been removed.
The OS map shows a 'tumulus' on Trink Hill (though it is not marked as scheduled on the Magic map) and close by, the Twelve O'clock Stone.
The sun strikes the flank of the Trink Hill "Twelve o'clock" stone, for example, using it as a dial; hence its name. When the stone "hears" cock-crow it turns itself; and would turn just as well as do others, in response to church bells or a striking clock, if it were within "hearing" of them. It is this stony "hearing" that has become a joke.
Oh do lighten up. It's only a story. From
The Stone Circles of Cornwall
B. C. Spooner
Folklore, Vol. 64, No. 4. (Dec., 1953), pp. 484-487.