But a short distance away, in the old graveyard north of the modern St. Feighin's Catholic church, the remains of a second medieval building sit quietly in the grass. What survives of St. Mary's is fragmentary but quietly eloquent: the footings of the north and south walls are largely grass-covered, a short stub of the west wall rises to about three metres, and the east gable still stands to its full height, draped in ivy. In the east wall, a single ogee-headed window, its spandrels plain and a hood-moulding above, gives the only real sense of architectural ambition. An ogee head is a pointed arch with a gentle S-curve to each side, a form common in late medieval Irish ecclesiastical building. The church itself was a simple, undivided rectangle of roughly coursed limestone rubble, measuring just under twenty metres in length and just over seven metres wide.

The foundation date is unknown, though the church was most likely established around the same time as the medieval borough of Fore. It first appears in the ecclesiastical taxation of 1302 to 1306, where the 'Church of St. Mary, Favorie' was valued at twenty shillings. After the dissolution of the monasteries, the property passed into secular hands: in 1567 Christopher Nugent, lord of Delvin, received a Crown lease covering the site and a sprawling collection of lands, rectories, and parsonages across Westmeath and Meath, at a rent of £175 10s 8d and with the obligation to maintain five horsemen. A separate five-year lease of overlapping lands was granted to William Dood in 1578 at a rent of £140. By the time Bishop Dopping carried out his diocesan visitation between 1682 and 1685, he recorded that the church had already fallen into disrepair before 1640, suggesting it had been abandoned for at least a generation by then.

The graveyard itself repays careful attention. Several dressed stones from the church, including a chamfered window mullion and a finial stone dating to the fifteenth or sixteenth century, have been repurposed as headstones, their carved surfaces now pressed into new service among the graves. Other cut stonework was incorporated into the enclosing boundary wall, which dates to after 1700. A trough-shaped piscina, a stone basin used for draining water after the rinsing of sacred vessels, was once recorded at the east end of the south wall, but it is no longer visible above ground.