The castle appears on the Down Survey Barony map from 1656-8, and by 1838 it was recorded as a square building measuring roughly 10 metres across. The Ordnance Survey Letters from that year describe “the ruins of a castle and bawne” in the townland of Farragh, though the defensive bawn wall that once surrounded the castle has left no trace behind.

The castle’s decline was swift; by the time surveyors returned in 1929, the building had vanished entirely, leaving only a notation on maps reading “Farragh Castle (Site of)”. The strategic positioning on the knoll wasn’t merely defensive; a stream was cleverly diverted around its eastern and southern base to power a flax mill that operated southeast of the castle. This mill, marked as already in ruins on the 1929 map, has also disappeared without trace.

Today, visitors to this quiet corner of Mayo will find little evidence of the castle that once commanded this spot, or of the industrial activity that buzzed nearby. The landscape has reclaimed both the medieval fortification and its later industrial neighbour, leaving only the gentle rise of the knoll and the meandering stream as hints of the site’s layered past.