The O'Carrolls of Ely once was the principal seat of the Original Tower House of Leap Castle. It once stood near the Slieve Bloom Mountains. In 1553, family rivalry broke out when The Chief of the Clan passed away. The Bloody Chapel is where "One-eyed Tadhg O'Carroll" killed his brother who was a priest. He was holding mass at the altar at the time of his death. A hidden room with a drop door was found near this chamber. Prisoners were hurled into this spiked oubliette and forgotten. The last use of the murder hole was in the seventeenth century. In 1599, Charles O' Carroll hired a force of MacMahons of Monaghan as mercenaries against the Earl of Tyrone. When their work was finished he got them drunk and had them all massacred in their sleep.
In 1695, Jonathan Darby married Charles O'Carroll's daughter therefore acquiring Leap Castle. It is said that he hid vast amounts of treasure on the grounds but after serving many years in prison for treason, he forgot where he hid them. They have yet to be recovered to this day. Leap Castle was said to be haunted even when the Darby family lived in it. A woman in a red gown clutching a radiant dagger was said to be seen by overnight guests. A foul smelling, elemental half human half beast that haunts the stairway overlooking the Hangman's Field encountered Mildred Darby. Until 1922 when it was burned, looted and plundered during the War of Independence, the Darby's remained in Leap Castle.
More Info: http://en.wikipedia.org/wiki/Leap_Castle