Spread across the townlands of Ballincolloo, Ballynamona, and Gormanstown, these linear cropmarks, visible from the air but absent from Ordnance Survey historic maps, have quietly resisted a definitive explanation for decades.

The site first came to attention on the 3rd of November 1984, when aerial photographs were taken as part of a survey for the Bórd Gáis Éireann Curraleigh West-Limerick gas pipeline. Analysts examining those images noted the perpendicular cropmarks, the kind of patterning that can indicate buried boundaries, ditches, or structural remains beneath the soil, and tentatively classified the site as a possible medieval settlement, associating it with Gormanstown Castle, which lies about 1.6 kilometres to the east. Cropmarks occur when buried features such as filled ditches or stone walls affect the moisture available to surface vegetation, causing differential growth that becomes legible from above, particularly in dry conditions. The interpretation gained some traction, not least because the site sits near a barrow complex, suggesting a landscape with a long history of human activity. However, later scrutiny of orthophotos taken between 2005 and 2013 complicated the picture. By March 2016, a Google Earth image showed the linear features as water-filled channels rather than dry earthworks, pointing toward a more prosaic origin: post-medieval drainage works connected with land reclamation on the estates of Ballincolloo House and Greenpark House, rather than any remnant of medieval settlement or a pre-1700 field system.

The site sits in reclaimed agricultural pasture and is not signposted or formally accessible. There is nothing to see at ground level; the cropmarks and channels are features best appreciated through aerial imagery, which remains the primary way researchers engage with the site. Anyone curious about the landscape can examine freely available satellite and orthophoto sources online, where the perpendicular lines remain clearly legible. The uncertainty around the site's origins is itself instructive: what looks like evidence of medieval life can turn out to be the handiwork of post-medieval estate managers draining boggy ground, and vice versa. That ambiguity is, in its own way, the most interesting thing about it.