The site came to light through orthophotography taken in 2000, in which a possible cropmark suggests a square enclosure of roughly 40 metres per side.

Cropmarks form when buried features, such as ditches, walls, or banks, affect the way crops grow above them. Soil over a filled ditch tends to retain more moisture, producing lusher, taller growth; soil over a buried wall drains more quickly, producing paler, shorter plants. Seen from above at the right time of year, these differences in vegetation can trace the outlines of structures long since vanished from the surface. The Knockanree cropmark, if it represents a genuine enclosure, would be a square form, which is somewhat less common in Ireland than the circular enclosures, known as raths or ringforts, that dot the landscape in their thousands. Square or rectangular enclosures can relate to a range of periods and functions, from early medieval settlement to earlier prehistoric activity, though without excavation or further survey, it is impossible to say anything definitive about what lies beneath this particular field. The site was brought to the attention of the National Monuments Service in 2013 by Ivor Kenny.