Small stone by Arran standards, which just adds to the incongruity of its location, on neatly manicured grass at the edge of a small car park. I'd not read the RCAHMS stuff below when I visited, but even without that, the idea that this may be the sole survivor of a cairn seemed plausible, there are a few in the immediate vicinity. There's bog all else to suggest it on the ground though, I guess the road and carpark have eradicated anything above ground. I can't recall any linear ridgey feature such as is mentioned below.
The other points of note are the views of the strange little island of Pladda, just offshore, and the lurking cone of Ailsa Craig on the horizon.
The ONB (1864) gives an alternative name of "Tumulus" for this feature, the surveyor's comments being "I have no authority for this object beyond its general appearance to warrant it being called a tumulus. There is a large standing stone, 3ft 7 ins x 3ft 6 ins x 6 ins (Balfour 1910) on the N side of it, with a smaller stone adjoining (not noticed by Balfour) The whole object is higher than the adjacent ground although partly levelled for the road." The words "giving the appearance of the remains of a stone circle" have been added by the examiner. Balfour adds "a stone circle, known to have existed here at one time, was removed when making the road".
A standing stone situated in a level grassy area and located approximately 30.0m from the edge of the coastal cliff. It is a plain weathered stone 1.1m high, 0.9m broad and 0.2m thick. A small (0.3m high) scarp runs southwestwards from the stone for 9.0m; it is not clear if this is artificial or merely an undulation in the ground. There is no surface evidence of either a cairn, a stone circle or the second "smaller" stone.