Interesting fact:

Philadelphia's Eastern State Penitentiary has a horrifying history, and many ghost hunters claim it's now a hive of haunted activity. Its 142-year history is scarred and stained by a litany of awful events, from suicides to torture to experiments on the mad inmates within. Methods of punishment carried out here included waterboarding and the use of an iron gag. If you fancy a visit, check out Cellblock 12 for cackling voices, Cellblock 6 for shadowy figures and for full ghostly figures, head to Cellblock 4, where a prison worker claimed to be seized by a violent negative energy.