What stands there today, now converted into an OPW heritage centre, is believed to occupy ground where grain was being ground for at least three and a half centuries.

The Civil Survey of 1654 to 1656, a detailed land inquisition carried out under Cromwellian administration to establish ownership and land use across Ireland, recorded two mills in the area. One was described as a 'Grinding Mill erected uppon a small River running through the sd towne', the other as 'a corne mill upon a brooke', both entries appearing in volume one of Robert Simington's 1931 edition of that survey. Whether these two descriptions refer to distinct structures on separate watercourses, or to the same site recorded twice with slight variation, is not entirely clear, but the Black Mills site is considered a probable location for at least one of them. By the time the six-inch Ordnance Survey was published in 1840, the place had acquired its distinctive name, rendered with a capital B and capital M, suggesting it was already well established in local memory and use.