A field system is exactly what the name suggests: the remains of ancient land division, usually visible as low earthen banks, stone boundaries, or ridge patterns that only become legible at a certain angle of light or from above. What makes these survivals quietly remarkable is their age. Field systems of this kind in the west of Ireland can date back several thousand years, their boundaries outlasting the civilisations that drew them simply because no one ever found a reason to plough them flat.

Mayo is particularly rich in this kind of evidence. The famous Céide Fields on the north Mayo coast, preserved beneath a blanket of bog, demonstrated that organised, enclosed farming landscapes existed in Ireland as far back as the Neolithic period, more than five thousand years ago. Field systems like the one recorded at Ballygarriff belong to a broader pattern of early agricultural organisation across the province, where communities divided the land into workable plots, managed livestock, and established boundaries that sometimes endured for generations. The specific history of the Ballygarriff system, its date, extent, and the people who made it, remains to be fully documented.