Ruined church situated centrally within graveyard. The church consists of an earlier nave (internal dimensions 10.7m x 7.5m) and of a later chancel (6.6m x 7.5m.). Traces of antae are preserved at either end of the N wall and at the E end of the S wall of the nave. A doorway inserted at the W end of the S wall with a now destroyed porch, has obliterated any trace of an antae at this angle. There is a plain pointed chancel arch (w. 1.95m) framed by a rectangular projection on both wall faces, and a pointed arch externally over SE door with a lintel on the interior, this doorway is framed by a similar rectangular projection. There is a single light slit in the S wall and a double ogee-headed light centrally positioned in the E wall.

Monastery founded on the site in 615 by St. Abban. According to the O.S. field books a church was founded here by John de Barry in 1295 and given, three years later, to the Knights Templar. A tooth of St. Patrick was reputedly kept here as a relic. During the 14thc. Coole was a considerable Episcopal manor, and the Bishop of Cloyne is reputed to have had a castle, and later a summer residence here. In 1642 a skirmish between the Condons and a company of Lord Barrymore's troops is recorded as having taken place within the church. The entire church is listed as being in ruins by 1694.

The rosette has been compared to similar features at Cormac's Chapel Cashel, and Roscrea, and based on this comparison has been dated to c. 1130 (O'Keeffe, 1994).