The ground shows nothing now, no ridge, no hollow, no crop-mark visible to a person walking the pasture. The only evidence that anything was ever there at all comes from a single aerial photograph taken in 1986, which caught the faint outline of a roughly rectangular earthwork pressed into the improved grassland below.

The site was identified as part of the Bruff aerial photographic survey carried out in 1986, catalogued under the reference Bruff 76, aerial photograph AP 4/3626. Aerial survey of this kind works by capturing anomalies in vegetation or soil that are invisible at ground level but briefly legible from above, particularly in dry summers when buried features cause overlying grass to grow at subtly different rates. Whatever the earthwork at Derk once was, it had already left no trace on any of the historic Ordnance Survey Ireland maps consulted by researchers, suggesting either that it had largely disappeared before those maps were made or that it was never prominent enough to be recorded by surveyors on the ground. By the time an OSi orthophoto was taken between 2005 and 2012, and again when Google Earth captured the area on 18 November 2018, no surface remains were visible at all. The record was compiled by Martin Fitzpatrick and uploaded in April 2021.

The location itself is specific, sitting in improved pasture approximately 25 metres east of a watercourse and 65 metres east of the townland boundary with Tonaree. Improved pasture, meaning land that has been drained, reseeded, and intensively managed for grazing, is particularly unforgiving to earthworks, since repeated ploughing and land improvement over generations can reduce even substantial features to nothing. A visitor to this area would find ordinary farmland with no public monument, no interpretive sign, and nothing to see. The interest here lies entirely in the negative space, a place that appears on one aerial photograph from nearly four decades ago and nowhere else, the kind of entry in an archaeological record that raises more questions than it resolves.