Dense tree growth and heavy overgrowth now ring it so thoroughly that getting a clear look at the structure is genuinely difficult, which makes it easy to overlook a site that was once conspicuously positioned to command wide views across the landscape.

A ringfort, or rath, is an enclosed circular or oval settlement, typically of early medieval date, defined by an earthen bank and an outer ditch known as a fosse. The Roslahan example is a raised oval area measuring roughly 40 metres on its north-to-south axis and about 35 metres east to west. Its bank still rises between 0.8 and 1 metre above the interior ground level, with a steep external slope dropping between 1.7 and 2 metres, and as much as 3 metres down to the base of the fosse at the north-east. A stone-lined entrance gap, about 2.6 metres wide, pierces the bank on the eastern side. On top of the bank, partially buried under moss, there is a remnant of a drystone wall, about 1.6 metres wide and up to 0.6 metres high, which appears to be of comparatively recent construction rather than original fabric. The fosse is most readable on the northern arc, where it survives as a broad depression 3 to 4 metres across, but it shallows out considerably elsewhere and has been obscured by a farm track on the south-western and western sides. A section of the bank and fosse at the north-west has been quarried away at some point, and a later field wall cuts across the northern edge of the monument on a rough north-west to south-east line. These intrusions are a reminder of how agricultural and practical needs have always negotiated, and sometimes overridden, the physical presence of earlier structures in the Irish countryside.