At Raheennahown in County Laois, a circular enclosure roughly thirty metres in diameter falls firmly into the second category. No upstanding remains mark the spot at ground level in any obvious way. Instead, the feature came to light through cropmark evidence, the phenomenon by which buried ditches and banks influence how vegetation grows above them, producing colour and texture variations that become visible in aerial or satellite imagery.

The enclosure was identified from Digital Globe orthoimages captured between 2011 and 2013, with further confirmation from Google Earth imagery. What the images show is a circular area defined by a low bank and a wide accompanying feature, most likely a ditch, forming the classic enclosed plan associated with a range of Irish archaeological site types. Circular enclosures of this kind are found across the Irish landscape in enormous numbers and span a broad chronological range, from prehistoric ring ditches and Bronze Age burial monuments through to early medieval raths, the farmstead enclosures that once sheltered rural households and their livestock across much of the island. Without excavation, it is impossible to assign Raheennahown's enclosure to any particular period or function, and the available evidence stops short of offering that kind of resolution.

What makes this site quietly interesting is precisely its invisibility on the ground. Raheennahown joins a long catalogue of Irish sites that exist, in practical terms, only because satellite technology and patient scrutiny of aerial imagery have made them findable. The earthwork is there beneath the fields; it simply requires a different kind of looking.