The monastery founded by St Feichin, probably sometime in the second quarter of the seventh century, was raided or burned at least sixteen times between 745 and 1176, a frequency that speaks less to vulnerability than to the wealth that made it worth attacking repeatedly. By the 1180s, when a Benedictine priory was established nearby, Feichin's original foundation had been effectively eclipsed, though the church itself continued in use as a parish church well into the later Middle Ages.

The building that survives is a nave-and-chancel structure in coursed limestone, but it grew in stages over several centuries. The nave, measuring 11.3 metres by 7.2 metres, is pre-twelfth century in date, while the chancel, a slightly smaller addition of 5.86 by 5 metres, was built in the thirteenth century and fitted carefully into the space created by the projecting antae, the short walls that extend beyond the nave's end corners, a feature characteristic of early Irish church architecture. In the fifteenth century the original twin-light east window was partly blocked and replaced by a single cusped ogee-headed window, the ogee being the double-curved arch form common in late medieval Irish ecclesiastical stonework. Beneath it, the altar table remains, carved with two equal-armed crosses. The chancel arch, which replaced most of the nave's east wall, is of pink sandstone, and on the lowermost springing stone of its north side, facing into the nave, a small figure has been carved: seated, hands on knees, legs crossed at the ankles, wearing a belted knee-length tunic, with a large round head and bulging eyes. The west door retains its massive lintelled frame, decorated in relief with a cross within a circle. By the time Bishop Dopping carried out his diocesan visitation between 1682 and 1685, the church was already a ruin. The ecclesiastical taxation of 1302 to 1306 had valued the Church of St Fechin at 26 shillings and 8 pence; by the late seventeenth century there was nothing left to value.

The church is part of a wider grouping of early medieval remains on the same side of the village, including a souterrain (an underground stone-lined passage, typically used for storage or refuge), an anchorite's cell, a second church known as Teampall Fionain, and St Feichin's mill. The carved figure on the chancel arch springing stone is easy to miss; it faces into the nave and sits low, where the arch begins its curve from the wall.