The cropmark, roughly eighteen metres across, traces the outline of an ancient enclosure defined by a double ditch, giving the whole feature an overall diameter of around twenty-eight metres. Cropmarks of this kind appear when buried features such as filled-in ditches or compacted banks cause the vegetation above them to grow at slightly different rates or change colour during dry periods, effectively printing a map of what lies underground onto the surface of the field.

The enclosure at Ballintober belongs to a well-attested tradition of circular enclosed sites in Ireland, which range from prehistoric ring-ditches to the more familiar ringforts of the early medieval period. A ringfort, sometimes called a rath, was typically a defended farmstead enclosed by one or more earthen banks and ditches, and examples with double ditches are generally associated with higher-status occupation. The relatively modest internal diameter here sits within the range of domestic enclosures rather than ceremonial monuments, though without excavation the precise date and function remain uncertain. Part of the feature has been cut away by a road running from the north-west toward the north, meaning the original circuit is no longer fully intact even at the level of the buried archaeology. The site came to wider notice through aerial imagery, and is discernible in Apple Maps photography, which has increasingly proved useful for identifying features of this kind across the Irish landscape.