The site consists of a prehistoric portal tomb, likely dating from the Neolithic period around 3,500 to 2,500 BCE, which has been rather unusually incorporated into a medieval gatehouse structure. The name translates to “Key of the Hag” or “Hag’s Chair”, reflecting the rich folklore that often attaches itself to ancient monuments throughout Ireland, where local tradition frequently attributes such structures to supernatural old women or goddesses.

The portal tomb itself follows the classic design found across Ireland; two tall upright stones support a massive capstone, creating a distinctive chamber that would have originally been covered by an earthen mound. What makes this particular site remarkable is how medieval builders chose to work around and with the ancient monument rather than dismantling it. The gatehouse, likely constructed several thousand years after the tomb, frames the prehistoric structure, creating an architectural palimpsest where different eras of Irish history literally stand side by side.

This layered history speaks to the reverence, or perhaps superstition, that medieval communities held for these ancient sites. Rather than clearing away the old stones to build anew, the gatehouse builders incorporated the portal tomb into their defensive structure, possibly recognising its significance to the local population or simply being practical about working with the immovable stone monument. Today, visitors can witness this extraordinary conversation between ages; a place where Bronze Age burial practices, medieval fortification, and centuries of folk tradition converge in the Mayo countryside.