By 1840, when the Ordnance Survey visited, only the east side of that castle and roughly four feet of its north and south walls still stood, rising to about thirty feet. The church itself had been partially rescued from ruin by then, its chancel re-roofed and pressed back into use as a Protestant parish church, while the roofless nave sat open to the sky beside it. The two halves of the same building, one functional and one crumbling, existed side by side for generations.

The church was known in medieval documents under several spellings, including Moyncroo, Maycroo, and Croch, and it appears in records from at least 1239, when a dispute over its advowson came to a head. An advowson was the right to appoint a priest to a church, a valuable and sometimes fiercely contested privilege. In this case, the prior of Athassel Abbey surrendered his claim to the Bishop of Limerick that year, though records suggest the controversy dragged on into the second half of the thirteenth century. By 1291 the place name appears as Croch, and by 1305 the vicarage and nearby manors had been taken into the hands of the Crown. In 1317 a legal dispute over lands here pitted Jordan Cotel against Robert and Isolda Lovelynch. The church itself was cruciform, meaning cross-shaped, with a nave, chancel, transepts, and a west tower, though the transepts were later demolished and their arches blocked up. The presentation, meaning the right to appoint clergy, was recorded in 1906 as belonging to the Earl of Desmond.

What survives today is a roofless nave and the partial remains of that west tower, with gables still standing to between six and seven metres. Visitors patient enough to examine the stonework will find ogee-headed windows, their arched heads curving in a double S-shape characteristic of late medieval Gothic work, as well as a decorated piscina in the chancel wall. A piscina is a small stone basin used for rinsing communion vessels, usually set into a wall niche near the altar, and the one here retains a large central drainage hole. Fragments of red sandstone appear in some of the window arches and the doorway, introduced among the predominant limestone rubble. The site is overgrown with ivy, which softens the stonework but also obscures detail, so a visit in late autumn or winter, when the ivy has thinned, will reward closer inspection of the remaining carved features.