Fire crews have spent much of the night battling a blaze in Belcarra, outside Castlebar.
The fire broke out yesterday evening at Bridgemount House - a historic two-storey property that was once the home of the late Dame Judy Coyne.
She and her husband founded the Knock Shrine Society in 1935 and spent years promoting Knock as a Marian Shrine.
It's understood the current occupiers of the house raised the alarm when they spotted smoke yesterday evening, and managed to escape without injury, while the house was destroyed by the blaze.
Members of the Castlebar Fire Service remain at the scene this morning, and Gardai say the scene has been preserved.