Not visible to the eye, not yet confirmed by excavation, but detectable through the quiet science of geophysical survey, there are traces of structures that may have stood inside this fortified enclosure centuries ago, roughly half a metre to nearly two metres down.

Between 2008 and 2009, Target Archaeological Geophysics carried out a series of surveys inside and outside the castle on behalf of the Balintober Community Group, with funding from the Heritage Council. The methods used, resistivity and gradiometry, measure subtle variations in the electrical properties and magnetic character of the soil respectively, and can reveal buried features such as walls, pits, and disturbed ground without lifting a spade. Those surveys, reported by Nicholls in 2008, identified numerous pits and the traces of at least two possible structures along the northern interior of the ward. One appears to be a circular hut-site; the other, immediately to its east, is roughly square, measuring approximately five metres in each direction, and may represent either an annexe to the first structure or an entirely separate building. Ground penetrating radar, which bounces pulses of energy through the earth to detect changes in buried deposits, was also applied to the site in 2009, but did not confirm these features. That discrepancy is not unusual: different geophysical techniques respond to different conditions in the soil, and the absence of a GPR signal does not rule out what the other methods suggested. The structures remain possible rather than proven, their exact nature and date still open questions.