This kind of feature, known as a cropmark, forms when buried ditches or banks affect how plants grow over them; where a ditch once cut through the soil, crops tend to grow taller and greener because the looser, moister fill retains more nutrients, and in dry conditions that difference becomes visible from the air as a distinct discolouration or tonal contrast against the surrounding field.

The feature at Haystown came to light not through a dedicated aerial survey but through the kind of quiet, methodical scrutiny of freely available satellite imagery that has become an increasingly productive way of identifying previously unrecorded archaeology across Ireland. The circular cropmark, approximately 23 metres in diameter, was identified on orthoimage data from both Apple Maps and a Google Earth image captured on 24 June 2018. The record was compiled by Caimin O'Brien, drawing on details provided by Jean-Charles Caillère, and was uploaded to the survey record in December 2022. The precise nature of the buried feature remains unconfirmed; a circular ditched enclosure of this scale could represent anything from a prehistoric ring-ditch or barrow to an early medieval enclosed settlement, and only targeted geophysical survey or excavation could clarify that question.

Because the feature exists only as a subsurface trace within an actively cultivated field, there is nothing visible on the ground to seek out in the conventional sense. The field itself is private agricultural land, and visitors should not attempt access without permission. The most instructive way to observe the feature is to examine the relevant satellite imagery directly, pulling up the coordinates in Google Earth and comparing the summer 2018 capture against other dates. Cropmarks of this kind are often most legible in late June or July, when a dry spell has stressed the crop sufficiently to reveal what lies beneath, so the timing of the original observation is no coincidence. The value of the site lies less in what can be seen in the landscape today and more in what it suggests about the density of unrecorded archaeology still waiting, field by field, to be noticed.