The rectangular outline, roughly fourteen and a half metres from east to west and six metres across, is now mostly readable as low mounds and overgrown foundation lines rather than standing masonry. The west end of the building is marked by no more than a slight dip in the ground. The east end fares a little better, where a low linear mound traces the line of the south wall, with a short section of external facing still visible. The most legible surviving feature is a limestone door jamb at the east end of the north wall, which in 1907 a local historian named Grove White recorded as still retaining its arch, measuring six feet two inches from ground to apex. That arch is gone now, but the jamb remains.

The church was known as Templetaggart, and its documented history stretches back to 1291, when it appeared in a Papal Taxation, a Europe-wide ecclesiastical survey that assessed the value of church properties to fund a crusade and which provides some of the earliest written records for many Irish parishes. By 1615 it was already described as being in ruins, suggesting the building had fallen out of use well before that date. The antiquary Charles Smith, writing in 1750, noted that the parish of Doneraile had formerly contained several chapels of ease at various locations including Rossagh; a chapel of ease was a secondary church built to serve parishioners who lived too far from the main parish church to attend regularly. That the site had been reduced to a footnote in an eighteenth-century account of former chapels gives some sense of how long it had been marginal to living religious practice. What the graveyard around it suggests, however, is that the place retained significance as a burial ground long after the building itself was beyond use.