This is a rath, the Irish term for a ringfort, the most common monument type surviving in the Irish countryside. Ringforts were typically enclosed farmsteads of the early medieval period, home to a single family and their livestock, defended by one or more earthen banks and ditches. The Boherascrub example measures roughly 36 metres north to south and 34 metres east to west, with an internal bank height of 1.3 metres and an external height of 1.9 metres. A gap of just over five metres in the bank to the west-north-west marks what was most likely the original entrance.

What gives this particular site a quietly layered quality is the evidence of its more recent past sitting alongside its ancient one. Field clearance material has been dumped against the outer face of the bank, suggesting the enclosure has served as a convenient field-corner repository at some point in the agricultural life of the land around it. More intriguing is the low platform running four metres wide outside the bank, defined by a scarp of around 0.4 metres. The 1842 Ordnance Survey six-inch map shows a second, outer bank at this location, and local information holds that this feature was levelled within living memory. What appears today as a barely perceptible earthwork is, in other words, the flattened remnant of a feature that still existed in the recollection of people alive when it was recorded. The 1842 map and the scarp together preserve the outline of something that was deliberately removed, not lost to centuries of erosion but to a deliberate decision, possibly to improve field drainage or ease the movement of machinery.