In a field near Ballymount in County Kildare, something circular lies just beneath the surface, invisible to anyone walking past but faintly legible from the sky. A roughly circular enclosure, approximately 26 metres in diameter, shows up not as upstanding earthworks but as a cropmark, the kind of ghostly outline that appears when buried features cause the vegetation or soil above them to dry out or grow differently from the surrounding land. In dry summers especially, these variations in crop colour or texture become readable from aerial photography in a way that centuries of ploughing and weathering have otherwise erased at ground level.

The enclosure at Ballymount was identified from Google Earth aerial imagery captured on 28 June 2018. What the imagery shows is a partial cropmark of the circular form, along with a second cropmark of an irregular shape immediately to the south, the relationship between the two features as yet unexplained. Circular enclosures of this general scale are commonly associated in Ireland with ringforts, the enclosed farmsteads that were the most typical unit of rural settlement from the early medieval period onwards, though without excavation it is impossible to say with any certainty what this particular feature represents or when it was made. The partial nature of the cropmark suggests either that only part of the original feature survives as a subsurface trace, or that soil and crop conditions on the day the image was taken only made part of it visible.