Where the more common ráth was raised from soil and sod, a cashel was constructed in stone, and in the limestone-rich landscape of Clare, such structures were a practical and enduring choice. The distinction matters because cashels tend to survive above ground more visibly than their earthen counterparts, their walls sometimes still coursed and readable after more than a thousand years.

Cashels of this type were typically built during the early medieval period, roughly between the fifth and twelfth centuries, and functioned as enclosed farmsteads for farming families of some local standing. The enclosing wall, which could be several metres thick and nearly as tall, defined a protected space for a household, its livestock, and its stores. Cahercalla, whose placename combines the Irish "cathair", meaning stone fort, with "calla", possibly referring to a lost personal name or a local topographical feature, fits into a dense pattern of such monuments across the Burren and its margins. Clare has an unusually high concentration of cashels, reflecting both the geology of the region and its settlement history during the centuries when these enclosures were in active use.