Local tradition records it as 'Muileann Iarn', meaning iron mill, and that name alone points to an industrial activity that has otherwise left almost no trace above ground. The only physical clue once visible were what people described as holes or round openings in the earth, features significant enough to be remembered but inconvenient enough that a former landowner's father filled them in to improve the agricultural land. The erasure was thorough. When the Ordnance Survey mapped the area in 1837, nothing in this field merited marking.

The fuller picture comes partly from a field roughly 440 metres to the north-east, where slag was recovered in 2003. Slag is the stony waste left behind when metal is smelted, and the pieces found here were assessed as having originated from a blast furnace, a technology that forces air through burning fuel and ore to achieve the high temperatures needed for iron production. Those fragments are now held in the National Museum of Ireland. Given that no trace of the site appeared on the 1837 survey, the operation had clearly wound down well before then, and a 17th-century date has been raised as a possibility. That era saw scattered attempts at iron production in parts of Ireland, often using local timber as charcoal fuel before woodland depletion made such ventures unsustainable. The filled-in openings, the recovered slag, and the persisting place name form a fragmentary but coherent picture of an industry that burned briefly and then vanished, preserved now mainly in a word that outlasted everything else.