A cashel is a type of ringfort defined by a stone rather than an earthen enclosure, and the one at Kiltaan known as Lisnagowan sits within a relict field system, the ghostly outline of boundaries long since abandoned, surrounded by rough pasture and hazel scrub. What makes it quietly strange is not just its company but its condition: a structure old enough to appear on the Ordnance Survey's twenty-five-inch plan of 1897 and their six-inch edition of 1920, yet still sufficiently intact to be measured in some detail, its drystone wall built from large horizontally laid blocks in double-faced construction.

The cashel encloses a subcircular area roughly fifteen metres north to south and fourteen and a half metres east to west internally, with the double-faced wall running between one and a half and two metres in width. Grass-covered rubble has accumulated on both the interior and exterior faces, suggesting a long period of gradual collapse rather than deliberate demolition. The probable original entrance, about 1.2 metres wide, sits at the south-east; its southern side is still marked by three large blocks stacked on top of one another, a detail that gives some sense of the care taken in the original construction. That entrance is now blocked. A modern cattle gap, cut at the western wall, has since taken over the practical business of getting animals in and out. By 1996, when the Record of Monuments and Places was compiled, the site had been categorised simply as an earthwork, a label that rather undersells the surviving stonework. Some ten metres to the west, machine clearance has removed vegetation across a wide area, and a barrier of spoil now separates the cashel from that disturbed ground.