The stones protrude just above the waterline roughly 200 metres south-east of the site of the former Cistercian monastery of Inishlounaght, and on the first edition Ordnance Survey six-inch map of 1840 to 1841 they appear as a small island, suggesting that even then the structure was already well on its way to becoming a river feature rather than a recognisable piece of engineering.

The Civil Survey of 1652 to 1654, a detailed land census carried out in the aftermath of the Cromwellian conquest, recorded three weirs on the River Suir, referred to in the document as the River of Sewer, lying between the lands of Inishlounaght and those of Greenan and Kilmacomma in County Waterford. By 1640 these weirs had been the property of the Cistercian monastery at Inishlounaght, a house of the order that had operated in this part of Tipperary for centuries. The survey also notes that at that time they were owned by one Patrick Goegh of Kilmanahan. A weir in this context was a barrier built across a river to raise the water level and direct fish into traps, a common and economically important feature of medieval monastic estates, since fish provided a reliable food source for communities bound by fasting rules. The surviving remains at Inishlounaght almost certainly extended across the full width of the river to the Waterford bank, making it a crossing-point between two counties as much as a fishing structure, and it may well be one of the three weirs the Civil Survey had in mind.