The one at Merlin Castle in Merlinpark, County Galway, does something rather different: it sits upside down, carved into the spandrel of a single-light ogee-headed window on the second floor of the castle's southern wall, tucked beneath a decorative motif with a six-petal marigold carved into the opposite corner of the same window frame. The inversion is what makes it peculiar. Sheelas are not typically placed this way, and the deliberateness of the positioning, paired with that floral companion carving, suggests a craftsman working with some specific intention, even if that intention is now lost.

The figure was not recorded until 2002, when Martin Fitzpatrick brought it to wider attention; it was subsequently described by the scholar Barbara Freitag in 2004. According to Freitag's description, the carving shows a round head with discernible facial features, indicated breasts, and both arms held straight in front of the body, the hands joined to touch a long vertical slit representing the vulva. The castle itself, Merlin Castle, is a tower house, the type of fortified residence built in considerable numbers across Connacht from the fifteenth century onward. The ogee-headed window, a style characterised by its double-curved arch, is a decorative detail associated with later medieval construction and points to a degree of ambition in the building's original fitout. That a sheela was carved into the fabric of such a window, and placed inverted within it, makes this one of the more quietly anomalous examples in the Irish record.