A cashel is a ringfort built from stone rather than earth and timber, its circular enclosing wall raised without mortar, relying on the weight and fit of the limestone to hold itself together. In the west of Ireland, where stone is abundant and timber scarce, this was the natural way to mark out a defended farmstead during the early medieval period, roughly 500 to 1200 AD. Thousands of these structures survive across the country, yet each one occupies its particular ground in its particular way, and the one at Poulbaun is no exception.

Clare is unusually dense with such monuments. The Burren alone contains some of the finest concentrations of cashels in Ireland, and the broader county landscape is scattered with enclosures that once sheltered farming families of middling rank, their cattle, and their stores. A cashel of this type would typically have served as the nucleus of a small agricultural holding, its thick stone wall offering protection against animal predators and rival neighbours rather than any organised military force. The name Poulbaun, likely derived from the Irish poll bán meaning white hole or pale hollow, suggests the kind of small descriptive placename that has attached itself to Irish townlands since people first began working the land here.