The antiquarian Austin Cooper visited the house in 1779 and found it in a state of disrepair. Joseph Holt, a general of the Society of the United Irishmen recorded in his memoirs that he spent a night in the ruin of Mount Pelier while on the run following the 1798 Rebellion. Holt wrote of his experience, "I lay down in the arched room of that remarkable building. I felt confident of the protection of the Almighty that the name of enchantment and the idle stories that were told of the place had but a slight hold of my mind." The Conollys sold the lands to Luke White in 1800. They passed through inheritance to the Massy family of Duntrileage, County Limerick. When the Massy family became bankrupt, the lands were acquired by the State. Today, the building is maintained by Coillte, who manage the forestry plantations on Mount Pelier's slopes, and have installed concrete stairs and iron safety rails across the upper windows.