Is Kilmainham Gaol haunted?
Ireland Reported haunting level 2 of 5

What actually happened
14 leaders of the 1916 Easter Rising were executed by firing squad in the Stonebreakers' Yard.
The history
Opened in 1796 as the county gaol for Dublin, it held Robert Emmet, Parnell and Countess Markievicz before closing in 1924. The State took it over in 1986 and the Office of Public Works runs it.
What people report
Visitors and guides have reported footsteps and lights in empty wings; the museum itself makes no such claim.
That paragraph is reported tradition, not a claim about what is there. The history above it is sourced; the stories are recorded because people tell them.
Visiting
Inchicore Road, Kilmainham, Dublin 8, D08 RK28, Ireland
Access is by guided tour only and tickets must be booked online in advance.