A cashel is a ringfort built from stone rather than earth, a type of enclosed farmstead most commonly associated with the early medieval period in Ireland, roughly between the fifth and twelfth centuries. Where the more familiar earthen ringfort, or rath, was thrown up from banked soil and timber, the cashel relied on whatever stone the local ground could offer, and in the west of Ireland that was rarely in short supply.

Ringforts of both kinds were the basic unit of rural settlement across early medieval Ireland, home to a farming family and their animals, defined by a circular enclosure that offered a modest degree of protection and a clear statement of territory. Thousands survive across the country in varying states of preservation, from well-maintained examples that read clearly as monuments to low, overgrown arcs that require some imagination to interpret. The cashel at Callow belongs to this wider pattern of settlement in Connacht, where stone construction became the default wherever the terrain made earthwork impractical or where good building material lay close to the surface.