The site represents a typical example of the tower houses that once dotted the Irish landscape during the late medieval period, built by local Gaelic lords or Anglo-Norman families who had long since adopted Irish customs. These fortified residences served dual purposes; they were both defensive strongholds and symbols of authority over the surrounding lands.

Archaeological evidence suggests the castle likely dates from the 15th or 16th century, when such structures proliferated across Connacht as local chieftains sought to consolidate their power during a turbulent era of shifting alliances and territorial disputes. The location at Rinnahulty would have offered clear sightlines across the approaches to the territory, allowing its inhabitants to spot potential threats or visitors well in advance. Like many Irish castles of its type, it probably consisted of a rectangular stone tower rising several storeys, with thick walls designed to withstand siege warfare and accommodation quarters in the upper levels.

The castle’s abandonment likely occurred during the upheavals of the 17th century, when Cromwell’s campaign and subsequent plantation policies saw many native Irish strongholds destroyed or confiscated. Today, visitors to the site can still make out the outline of the castle’s footprint amongst the overgrowth, with scattered stones hinting at the substantial structure that once commanded this quiet corner of Mayo. Local tradition maintains various stories about the castle’s former inhabitants, though separating folklore from historical fact remains challenging given the scarcity of documentary evidence from the period.