But those rushes are doing something useful. On the eastern side of the site, they trace the course of a fosse, the encircling ditch that once defined the outer boundary of a rath, as ringforts of this type are commonly known in Ireland. A rath is a roughly circular earthwork enclosure, typically dating from the early medieval period, that would have enclosed a farmstead and provided a degree of social status as much as physical defence. Here at Dromagarraun, that circle has been interrupted. A field boundary cuts across the northern side, reducing what was a complete ring into something closer to an arc, and shrinking the measurable north-south distance from field boundary to interior edge to just over twenty metres, against an original east-west diameter of twenty-nine metres.

The notes compiled by Denis Power, uploaded to the record in August 2011, describe the surviving enclosing element as a scarped edge, meaning a slope cut deliberately into the ground rather than built up, standing only about a quarter of a metre high and roughly three metres wide. The external fosse matches those modest dimensions. On the western side it is barely visible at all, but the eastern section retains enough moisture to sustain that telling stand of rushes, which acts as an accidental but reliable marker. The interior of the enclosure slopes upward gently toward its centre, a characteristic feature of many raths, and the whole site lies under continuous grass with no visible stonework or later disturbance recorded beyond the field boundary intrusion.

Dromagarraun sits in undulating marshy pasture, which makes the ground conditions worth bearing in mind before visiting. Waterproof footwear would be sensible in any season, but particularly between autumn and spring when the low-lying areas around the fosse are likely to be soft underfoot. The rushes on the eastern side are the most reliable visual guide to the line of the ditch; on the western approach the earthwork offers very little to the eye at ground level, and the slight central rise of the interior is best appreciated by walking into the enclosed area and looking back outward. The site is entirely under grass, so nothing will be disturbed by a careful visit, but equally there is nothing to read or examine beyond the landform itself, which rewards patience and a willingness to let the eye adjust to very subtle topography.