These sites, found in their thousands across Ireland, are among the most common prehistoric monuments in the country, and yet what exactly they were used for is still a matter of debate. The leading theory is that they served as cooking sites, where stones were heated in a fire and dropped into a trough of water to bring it to the boil. Other theories have proposed uses ranging from textile processing to bathing. What is not in doubt is the fire: the defining feature of any fulacht fia is the mound of cracked and blackened stone left behind after repeated heating and cooling cycles, and at Ballyrobert that burnt material survives in notable quantity.

The site sits roughly midway between the northern bank of the Bride river and St. Bridget's Well, a pairing that would have made good practical sense to whoever used the site in prehistory. Fulachtaí fia almost always appear near water, whether a river, a spring, or naturally boggy ground, and the wet pasture here fits that pattern precisely. The association with St. Bridget's Well is a coincidence of proximity rather than any direct connection; holy wells, which are early Christian or pre-Christian sacred springs later absorbed into the cult of local saints, belong to a different chapter of the landscape's history entirely. Still, it is a suggestive arrangement: fire, water, and a place of veneration all within a short distance of one another on the same stretch of low-lying ground beside the Bride.