The Abbey of St Catherine de O’Conyl (Manisternagalliaghduff) is a ruined 13th-century Augustinian abbey located on private land near the village of Shanagolden in county Limerick.
According to folklore, an order was given by Pope Martin V in 1432 to wind up the abbey, following allegations of witchcraft and debauchery made against the abbess.

The ruin of the church features two small rooms, one of which served as a sacristy. It is in this room where the abbess was said to dabble in the black arts and engage in sexual acts. When the other nuns left the abbey, she remained there alone. As the building surrounding her slowly deteriorated, so did she. Supposedly poisoned by her black practices, her skin began to darken, and it is for this reason that the Abbey of St Catherine de O’Conyl is often referred to as “The Abbey of the Black Hag”. Her ghost now haunts the former sacristy where she practiced her craft.

Another legend associated with the site relates to the Countess of Desmond. While fleeing from an attack, she was struck down by an arrow and was quickly buried in a makeshift grave. But she was not dead. Her distressed ghost drew the attention of locals and when her body was exhumed, they found that her fingers were worn down to the bone, clawing at the stones that had been piled upon her. Unsurprisingly, the poor soul is still believed to haunt the abbey and her screams can sometimes be heard echoing throughout the site.