The building standing there today dates from 1825. The community it commemorates was founded nearly two centuries earlier, on the same ground, and vanished so completely that nothing of it survives above the surface.

In 1649, a community of Poor Clares, the contemplative branch of the Franciscan order bound by a rule of radical poverty, was granted a site on what was then known as Oileán Ealtanach by the Corporation of Galway. The timing was difficult from the outset. The community was established during a period of profound instability in Ireland, and by 1653, just four years after its founding, the convent was abandoned. The nuns returned briefly in the 1660s, but the occupation did not last. By around 1691, the community had relocated to a house on Market Street, within the town proper, leaving the island site behind. What caused the repeated displacement is not spelled out in the surviving record, but the Cromwellian campaigns of the early 1650s, which brought the siege and fall of Galway in 1652, offer an obvious context. A small religious community on an island just outside the town walls would have been acutely exposed to whatever followed that upheaval. The island's earlier Irish name, Oileán Ealtanach, faded in favour of the name that preserved the memory of the community itself, even as every physical trace of their seventeenth-century house disappeared.