Built during the late medieval period, likely in the 15th or 16th century, the structure served as both a defensive fortification and a residence for a local Gaelic or Anglo-Norman family. Tower houses like this one emerged across Ireland during a time of political fragmentation, when local lords needed fortified homes that could withstand raids whilst still providing comfortable living quarters for their households.

The tower’s construction follows the typical pattern of Irish tower houses, with thick stone walls, narrow windows, and multiple storeys connected by a spiral staircase built into the walls. These buildings were ingeniously designed; the ground floor typically stored provisions and sometimes housed livestock, whilst the upper floors contained the main hall and private chambers. The battlements at the top allowed defenders to survey the surrounding countryside and rain down missiles on any attackers foolish enough to approach. Though now roofless and partially ruined, the remaining stonework reveals the skill of medieval masons who created a structure sturdy enough to survive centuries of Irish weather.

Today, Castleaffy tower house stands as a quiet monument to a turbulent era when such fortifications dotted the Irish landscape. Its location in rural Mayo means it receives few visitors, allowing those who do make the journey to experience an authentic piece of medieval architecture without crowds or commercialisation. The surrounding pastoral landscape has changed little over the centuries, making it easy to imagine how the tower’s inhabitants once kept watch over their cattle, crops, and kinsmen from these ancient walls.