#8: Leap Castle, County Offaly, Ireland
Widely regarded as one of the most intensely haunted fortresses in Europe, this stone stronghold was the site of a savage clan massacre in 1532. During a holy mass, a ruthless chieftain brutally murdered his own brother—a priest—directly in front of the altar, permanently staining the chapel with blood. The site’s dark legacy was further solidified in 1922 when workers discovered a hidden oubliette packed with a cartload of human skeletons.

