The Abbey was founded by Norbertine Monks who it is believed were already established in the parish at this time. It is possible the Abbey and its townland are now known as Kildermott (Cill Diarmuda: Dermots church) due to patronage by the McDermott Lordships during the reign of Henry 8th. No connection with a Saint of that name can be traced.
The Abbey was partially destroyed after the Cromwellian Act of 1697 persecuting the Catholic Faith at which time the McDermott Lordships lost their freeholds in the parish. Two Holy Water Fonts from the Abbey were recovered from the lake by a Mr. Thomas Gallagher where they were presumably dumped. One has been returned to the Abbey whilst the other resides in the National Museum.
In the Ordinance Survey Field Name Book of 1838 there is a note:
"In the north of the parish, on the N.W. margin of Ballymore lake, there stands within a graveyard the ruined church of Kildermot. Its western gable is pulled down to the ground, but its foundation is still traceable. Its side walls are intact, and its eastern gable remains standing.
In this gable is a lancet window, widened inside and arched above. It is between 3 and 4ft. high on the outside and 6ft. high on the inside; its outside breadth averages about 6 inches. It commences within 2 or 3ft. of the ground and rises to the height of the side walls; it is fashioned of rudely cut stones. The whole church, on the inside, was only 18ft. by 12ft.
To the west of this church was another building, about 31ft. in length and somewhat wider than Kildermot, as appears by its foundations."
Kildermott Abbey was declared a National Monument in 1939.
"Dawn Mass" is celebrated annually at the ruins on Easter Sunday morning. What a spectacular site to watch the sun rise over Ballymore Lake.
By Della Ginley