They have been that way for the better part of two centuries, their circular outlines scored into the Old Red Sandstone conglomerate but never fully freed from the parent rock. Nearby, two more stones were cut loose and shaped to a point, then abandoned before they could be put to use. Whatever interrupted the work, it left behind an unusually legible record of a craft that normally vanishes into the finished product.

The quarry sits in the inter-tidal zone at Templetown, and the method reportedly used here was as clever as it was dependent on local conditions. Wooden wedges were driven into scored lines in the rock, and the rising tide would soak and swell the timber, exerting enough pressure to split the rough disc free from the bedrock. Once separated, the heavy stones were loaded onto barges and floated away, the sea doing the work of transport as well as extraction. The earliest documentary reference to the site dates to 1736, cited by historian Colfer in 2004, and Lewis's topographical survey of 1837 confirms it was still active in the early nineteenth century. The stone itself, Old Red Sandstone conglomerate, is a sedimentary rock common along this stretch of the Irish coast, its coarse texture making it well suited to the grinding surfaces of a millstone.

The stones in progress measure between 1.4 and 1.5 metres in diameter, which gives some sense of the scale of work involved and the physical effort required to manage such pieces on a tidal platform. The site is accessible only when the tide is out, so timing matters, and the cliffs rising immediately to the east mean the platform can be in shadow for much of the day. The unfinished stones are not monuments in any formal sense; they are simply work that stopped, sitting where they were left, wearing the same slow weathering as everything else on the shore.