A cashel is a stone-walled enclosure, typically circular or roughly oval, built in early medieval Ireland to define and defend a farmstead or settlement. This one at Cragreagh is rectangular, which is itself a less common form, and the building nestled inside it makes use of the cashel's own southern and eastern walls as two of its four sides, a practical arrangement that speaks to a certain economy of effort and material.

The structure is modest in scale: internally it measures roughly 4.6 metres east to west and 2.7 metres north to south, about the footprint of a large garden shed. Its western and northern sides are formed by a stone wall that is now grassed over and survives to only around half a metre in external height. A single inner wall-facing stone, still visible mid-way along the northern wall, is a small but telling detail, the kind of remnant that hints at more substantial construction now lost to time and soil accumulation. Just to the north of the building lies a pond, its western and northern edges defined by another low stone bank. Whether the pond predates the building, was created alongside it, or accumulated later is not recorded, but its proximity to a domestic structure suggests it may have served a practical purpose for whoever once lived here. The date of occupation remains unestablished.