The "discovery" image
This is the original "discovery" image, taken by Dr. J.K. Joseph for the Cambridge University Collection of Aerial Photographs (CUCAP) in the early 1970s. It appears to show a "crop mark" revealing two concentric circular shapes and perhaps a bigger circular shape. This orientation of the image is roughly looking south. The road is the R177 Dundalk to Armagh road. At the time of this photo, Carnbeg was under tillage.
It wasn't until 1988 that the archaeologist Victor Buckley saw this image and proposed that it might show the remains of Wright's Ballynahatne site which he drew about 240 years earlier.
The small circular feature to top left of image is a quarry which was opened at some time in recent centuries. In a 1737 map of the Carnbeg estate, a field here is marked "Quarry Field".