This site is of disputed antiquity. If you have any information that could help clarify this site's authenticity, please post below or leave a post in the forum.
This site I found coming to a four field junction (one quarter of which is the SE corner of the Knowe of Angcrow field) and looking ESE across, my attention having been drawn by several black-and-white cows lying down. This is in the northern corner of a field where a pond is currently. They were at on one end of a depression (very approx. HY236170) that looks to hold the remains of a possible prehistoric structure at the other, represented by a low rectangular outlined collection of large slabs at various angles. In the 19th century there are in this field no map legends or freestanding water.
What the 1882 map shows is a slender marshy margin to the eastern field boundary. This margin is more noticeable on that map in the next field north, where to its west a rectangular ?enclosure is shown occupying the SE corner of the field (roughly a third of the field's length long) with the Knowe of Angerow beyond that.
I can think of two possible periods for the stones off the top of my head, pre-Pictish and late Viking (any later and I cannot doubt a name would have survived for antiquarians to note), though I am strongly inclined to the former because not all the slabs are of the same shape (unlike Spots in the Caldale valley to which there is otherwise similarity). The simplest solution is that the stones were uncovered during drainage works late last century, certainly an atypical clearance heap if it were otherwise.