What makes the place quietly peculiar is a detail buried in an early seventeenth-century church record: in 1615, the parish of Ballyvalloo was impropriate to a leper hospital, meaning the revenues of the church were assigned to that institution rather than to a resident clergyman. The arrangement was noted during a visitation by Thomas Ram, the Protestant bishop of Ferns, who recorded that a curate named Nicholas Rochford was serving the parish and that both the church and its chancel were still in good repair at that time.

Four centuries later, rather less survives. The ruins sit within a raised oval graveyard, its perimeter defined by a masonry wall, and the footprint of both nave and chancel can still be read in the grass-covered spread of mortared shale walls, which stand around three metres high in places. The most complete feature remaining is a rounded chancel arch, the narrow transitional opening between nave and chancel, built from uncut stone and now heavily draped in ivy. A window opening once pierced the east wall of the chancel, but it has been destroyed. About a hundred metres to the east lay the site of St Peter's Well, where patterns, the traditional Irish gatherings of prayer and communal celebration held on a saint's feast day, took place each year on the 29th of June. John O'Donovan, the nineteenth-century scholar and place-name researcher, recorded the custom around 1840, though the precise location of the well has since been lost.