The earthwork, known as a rath, was levelled around 1979, almost certainly during agricultural improvement works, its encircling banks and ditches ploughed flat to make the ground easier to till. That act of clearance is not unusual in the Irish landscape; thousands of ringforts, the circular enclosed farmsteads that once dotted the countryside in their tens of thousands during the early medieval period, were removed during the twentieth century as farm mechanisation made such earthworks inconvenient obstacles.

What the levelling could not easily erase was the souterrain recorded within the fort's interior. A souterrain is an underground stone-lined passage or chamber, typically dug during the early medieval period to serve as a place of refuge, storage, or ventilation for a dwelling above. These subterranean structures often outlast the surface remains with which they were associated, surviving as voids beneath fields long after every visible trace of the enclosure itself has gone. Whether the souterrain at Bengour remains intact beneath the cultivated soil, or was disturbed at the same time as the earthwork above it, is not recorded.