Very little in known about Coole Abbey. The present ruin dates from about the twelfth or thirteenth century and possesses some features which are characteristic of some early stone built churches. One of the these features is the stone built on the south and north walls and this is thought to have come from a period when churches were constructed of wood and these projections were used to support the timber beams of the roof. The west end of the church is thought to have been added later as were the buildings to the north and south, of whuch only the foundations remain today.
The second church in Coole is situated in Coole graveyard, and is slightly larger in size than Coole Abbey. It is an example of an early Irish stone church. This building was in use until the 18th century and a number of small additions had been made to it from time to time.
The foundation of the church in Coole is attributed to Saint Abban, but due to the confusion over the history of early Irish Saints this may not be accurate. Other churches said to have been founded by St. Abban are all in the dioceses of Cloyne and are either in the territory of Uí Liathain or of Clongibbon. Another saint said to have been associated with the church at Coole is St. Dalbach who belonged to a branch of the Uí Liathain. He died in 779 A.D. and his feast day was siad to have been 23rd October.
The ancient village of Coole is two miles east of Castlelyons. It is the only known village that can boast to having a blessed well, two churches and a graveyard all inthe one field.